ONLINE PAYMENT FORM

Thursday, February 18, 2016

5- CONSERVATORSHIP LAWS IN ELDERLY OR OLDER PEOPLE HELP AND ADULT PSYCHIATRY

THE IS SHARED ONLINE JOURNAL.

 

                                                                                               AUTHOR.MR.FELIX ATI-JOHN

 

ACADEMIC WRITING

 

SUBJECT -   CONSERVATORHIP LAWS IN ELDERLY OR OLDER PEOPLE HELP

AND ADULT  PSYCHIATRY


External validity

From Wikipedia, the free encyclopedia
Jump to: navigation, search
External validity is the validity of generalized (causal) inferences in scientific research, usually based on experiments as experimental validity.[1] In other words, it is the extent to which the results of a study can be generalized to other situations and to other people.[2]


Threats to external validity[edit]

"A threat to external validity is an explanation of how you might be wrong in making a generalization."[3] Generally, generalizability is limited when the cause (i.e. the independent variable) depends on other factors; therefore, all threats to external validity interact with the independent variable - a so-called background factor x treatment interaction.[4]
  • Aptitude–treatment Interaction: The sample may have certain features that may interact with the independent variable, limiting generalizability. For example, inferences based on comparative psychotherapy studies often employ specific samples (e.g. volunteers, highly depressed, no comorbidity). If psychotherapy is found effective for these sample patients, will it also be effective for non-volunteers or the mildly depressed or patients with concurrent other disorders?
  • Situation: All situational specifics (e.g. treatment conditions, time, location, lighting, noise, treatment administration, investigator, timing, scope and extent of measurement, etc. etc.) of a study potentially limit generalizability.
  • Pre-test effects: If cause-effect relationships can only be found when pre-tests are carried out, then this also limits the generality of the findings.
  • Post-test effects: If cause-effect relationships can only be found when post-tests are carried out, then this also limits the generality of the findings.
  • Reactivity (placebo, novelty, and Hawthorne effects): If cause-effect relationships are found they might not be generalizable to other settings or situations if the effects found only occurred as an effect of studying the situation.
  • Rosenthal effects: Inferences about cause-consequence relationships may not be generalizable to other investigators or researchers.
Cook and Campbell[5] made the crucial distinction between generalizing to some population and generalizing across subpopulations defined by different levels of some background factor. Lynch has argued that it is almost never possible to generalize to meaningful populations except as a snapshot of history, but it is possible to test the degree to which the effect of some cause on some dependent variable generalizes across subpopulations that vary in some background factor. That requires a test of whether the treatment effect being investigated is moderated by interactions with one or more background factors.[6][7]

External, internal, and ecological validity[edit]

In many studies and research designs, there may be a "trade-off" between internal validity and external validity: When measures are taken or procedures implemented aiming at increasing the chance for higher degrees of internal validity, these measures may also limit the generalizability of the findings. This situation has led many researchers call for "ecologically valid" experiments. By that they mean that experimental procedures should resemble "real-world" conditions. They criticize the lack of ecological validity in many laboratory-based studies with a focus on artificially controlled and constricted environments. Some researchers think external validity and ecological validity are closely related in the sense that causal inferences based on ecologically valid research designs often allow for higher degrees of generalizability than those obtained in an artificially produced lab environment. However, this again relates to the distinction between generalizing to some population (closely related to concerns about ecological validity) and generalizing across subpopulations that differ on some background factor. Some findings produced in ecologically valid research settings may hardly be generalizable, and some findings produced in highly controlled settings may claim near-universal external validity. Thus, External and Ecological Validity are independent – a study may possess external validity but not ecological validity, and vice versa.

Qualitative research[edit]

Within the qualitative research paradigm, external validity is replaced by the concept of transferability. Transferability is the ability of research results to transfer to situations with similar parameters, populations and characteristics.[8]

External validity in experiments[edit]

It is common for researchers to claim that experiments are by their nature low in external validity. Some claim that many drawbacks can occur when following the experimental method. By the virtue of gaining enough control over the situation so as to randomly assign people to conditions and rule out the effects of extraneous variables, the situation can become somewhat artificial and distant from real life.
There are two kinds of generalizability at issue:
  1. The extent to which we can generalize from the situation constructed by an experimenter to real-life situations (generalizability across situations),[9] and
  2. The extent to which we can generalize from the people who participated in the experiment to people in general (generalizability across people)[10]
However, both of these considerations pertain to Cook and Campbell's concept of generalizing to some target population rather than the arguably more central task of assessing the generalizability of findings from an experiment across subpopulations that differ from the specific situation studied and people who differ from the respondents studied in some meaningful way.[11]
Critics of experiments suggest that external validity could be improved by use of field settings (or, at a minimum, realistic laboratory settings) and by use of true probability samples of respondents. However, if one's goal is to understand generalizability across subpopulations that differ in situational or personal background factors, these remedies do not have the efficacy in increasing external validity that is commonly ascribed to them. If background factor X treatment interactions exist of which the researcher is unaware (as seems likely), these research practices can mask a substantial lack of external validity. Dipboye and Flanagan (1979), writing about industrial and organizational psychology, note that the evidence is that findings from one field setting and from one lab setting are equally unlikely to generalize to a second field setting.[12] Thus, field studies are not by their nature high in external validity and laboratory studies are not by their nature low in external validity. It depends in both cases whether the particular treatment effect studied would change with changes in background factors that are held constant in that study. If one's study is "unrealistic" on the level of some background factor that does not interact with the treatments, it has no effect on external validity. It is only if an experiment holds some background factor constant at an unrealistic level and if varying that background factor would have revealed a strong Treatment x Background factor interaction, that external validity is threatened.[13]

Generalizability across situations[edit]

Research in psychology experiments attempted in universities are often criticized for being conducted in artificial situations and that it cannot be generalized to real life.[14] To solve this problem, social psychologists attempt to increase the generalizability of their results by making their studies as realistic as possible. As noted above, this is in the hope of generalizing to some specific population. Realism per se does not help the make statements about whether the results would change if the setting were somehow more realistic, or if study participants were placed in a different realistic setting. If only one setting is tested, it is not possible to make statements about generalizability across settings.[15][16]
However, many authors conflate external validity and realism. There is more than one way that an experiment can be realistic:
  1. The similarity of an experimental situation to events that occur frequently in everyday life—it is clear that many experiments are decidedly unreal.
  2. In many experiments, people are placed in situations they would rarely encounter in everyday life.
This is referred to the extent to which an experiment is similar to real-life situations as the experiment's mundane realism.[17]
It is more important to ensure that a study is high in psychological realism—how similar the psychological processes triggered in an experiment are to psychological processes that occur in everyday life.[18]
Psychological realism is heightened if people find themselves engrossed in a real event. To accomplish this, researchers sometimes tell the participants a cover story—a false description of the study's purpose. If however, the experimenters were to tell the participants the purpose of the experiment then such a procedure would be low in psychological realism. In everyday life, no one knows when emergencies are going to occur and people do not have time to plan responses to them. This means that the kinds of psychological processes triggered would differ widely from those of a real emergency, reducing the psychological realism of the study.[19]
People don't always know why they do what they do, or what they do until it happens. Therefore, describing an experimental situation to participants and then asking them to respond normally will produce responses that may not match the behavior of people who are actually in the same situation. We cannot depend on people's predictions about what they would do in a hypothetical situation; we can only find out what people will really do when we construct a situation that triggers the same psychological processes as occur in the real world.

Generalizability across people[edit]

Social psychologists study the way in which people in general are susceptible to social influence. Several experiments have documented an interesting, unexpected example of social influence, whereby the mere knowledge that others were present reduced the likelihood that people helped.
The only way to be certain that the results of an experiment represent the behaviour of a particular population is to ensure that participants are randomly selected from that population. Samples in experiments cannot be randomly selected just as they are in surveys because it is impractical and expensive to select random samples for social psychology experiments. It is difficult enough to convince a random sample of people to agree to answer a few questions over the telephone as part of a political poll, and such polls can cost thousands of dollars to conduct. Moreover, even if one somehow was able to recruit a truly random sample, there can be unobserved heterogeneity in the effects of the experimental treatments... A treatment can have a positive effect on some subgroups but a negative effect on others. The effects shown in the treatment averages may not generalize to any subgroup.[20][21]
Many researchers address this problem by studying basic psychological processes that make people susceptible to social influence, assuming that these processes are so fundamental that they are universally shared. Some social psychologist processes do vary in different cultures and in those cases, diverse samples of people have to be studied.[22]

Replications[edit]

The ultimate test of an experiment's external validity is replication — conducting the study over again, generally with different subject populations or in different settings. Researches will often use different methods, to see if they still get the same results.
When many studies of one problem are conducted, the results can vary. Several studies might find an effect of the number of bystanders on helping behaviour, whereas a few do not. To make sense out of this, there is a statistical technique called meta-analysis that averages the results of two or more studies to see if the effect of an independent variable is reliable. A meta analysis essentially tells us the probability that the findings across the results of many studies are attributable to chance or to the independent variable. If an independent variable is found to have an effect in only of 20 studies, the meta-analysis will tell you that that one study was an exception and that, on average, the independent variable is not influencing the dependent variable. If an independent variable is having an effect in most of the studies, the meta analysis is likely to tell us that, on average, it does influence the dependent variable.
There can be reliable phenomena that are not limited to the laboratory. For example, increasing the number of bystanders has been found to inhibit helping behaviour with many kinds of people, including children, university students, and future ministers;[23] in Israel;[24] in small towns and large cities in the U.S.;[25] in a variety of settings, such as psychology laboratories, city streets, and subway trains;[26] and with a variety of types of emergencies, such as seizures, potential fires, fights, and accidents,[27] as well as with less serious events, such as having a flat tire.[28] Many of these replications have been conducted in real-life settings where people could not possibly have known that an experiment was being conducted.

The basic dilemma of the social psychologist[edit]

When conducting experiments in psychology, some believe that there is always a trade-off between internal and external validity—
  1. having enough control over the situation to ensure that no extraneous variables are influencing the results and to randomly assign people to conditions, and
  2. ensuring that the results can be generalized to everyday life.
Some researchers believe that a good way to increase external validity is by conducting field experiments. In a field experiment, people's behavior is studied outside the laboratory, in its natural setting. A field experiment is identical in design to a laboratory experiment, except that it is conducted in a real-life setting. The participants in a field experiment are unaware that the events they experience are in fact an experiment. Some claim that the external validity of such an experiment is high because it is taking place in the real world, with real people who are more diverse than a typical university student sample. However, as real-world settings differ dramatically, findings in one real world setting may or may not generalize to another real world setting.[29]
Neither internal nor external validity are captured in a single experiment. Social psychologists opt first for internal validity, conducting laboratory experiments in which people are randomly assigned to different conditions and all extraneous variables are controlled. Other social psychologists prefer external validity to control, conducting most of their research in field studies. And many do both. Taken together, both types of studies meet the requirements of the perfect experiment. Through replication, researchers can study a given research question with maximal internal and external validity.[30]

See also[edit]

Notes[edit]

  1. Jump up ^ Mitchell, M. & Jolley, J. (2001). Research Design Explained (4th Ed) New York:Harcourt.
  2. Jump up ^ Aronson, E., Wilson, T. D., Akert, R. M., & Fehr, B. (2007). Social psychology. (4 ed.). Toronto, ON: Pearson Education.
  3. Jump up ^ Trochim, William M. The Research Methods Knowledge Base, 2nd Edition.
  4. Jump up ^ Lynch, John (1982). "On the External Validity of Experiments in Consumer Research". Journal of Consumer Research 9 (3): 225–239. doi:10.1086/208919. Retrieved December 2, 2010. 
  5. Jump up ^ Cook, Thomas D.; Campbell, Donald T. (1979). Quasi-Experimentation: Design & Analysis Issues for Field Settings. Chicago: Rand McNally College Publishing Company. ISBN 978-0395307908. 
  6. Jump up ^ Lynch, John (1982). "On the External Validity of Experiments in Consumer Research". Journal of Consumer Research 9 (3): 225–239. doi:10.1086/208919. Retrieved December 2, 2010. 
  7. Jump up ^ Lynch, John (1999). "Theory and External Validity" (PDF). Journal of the Academy of Marketing Science 27 (3): 367–76. 
  8. Jump up ^ Lincoln, Y.S. & Guba, E.G. (1986). But is it rigorous? Trustworthiness and authenticity in naturalistic evaluation. In D.D. Williams (Ed.), Naturalistic evaluation (pp. 73-84). New Directions for Program Evaluation, 30. San Francisco, CA: Jossey-Bass.
  9. Jump up ^ Aronson, E., Wilson, T. D., Akert, R. M., & Fehr, B. (2007). Social psychology. (4 ed.). Toronto, ON: Pearson Education.
  10. Jump up ^ Aronson, E., Wilson, T. D., Akert, R. M., & Fehr, B. (2007). Social psychology. (4 ed.). Toronto, ON: Pearson Education.
  11. Jump up ^ Cook, Thomas D.; Campbell, Donald T. (1979). Quasi-Experimentation: Design & Analysis Issues for Field Settings. Chicago: Rand McNally College Publishing Company. ISBN 978-0395307908. 
  12. Jump up ^ Dipboye, Robert L.; Flanagan, Michael F. (1979). "Research Settings in Industrial and Organizational Psychology: Are Findings in the Field More Generalizable than the Laboratory". American Psychologist 34 (2): 141–150. doi:10.1037/0003-066x.34.2.141. 
  13. Jump up ^ Lynch, John (1982). "On the External Validity of Experiments in Consumer Research". Journal of Consumer Research 9 (3): 225–239. doi:10.1086/208919. 
  14. Jump up ^ Aronson, E., & Carlsmith, J.M. (1968). Experimentation in social psychology. In G. Lindzey & E. Aronson(Eds.), The Handbook of social psychology. (Vol. 2, pp. 1-79.) Reading, MA: Addison-Wesley.
  15. Jump up ^ Lynch, John (1982). "On the External Validity of Experiments in Consumer Research". Journal of Consumer Research 9 (3): 225–239. doi:10.1086/208919. Retrieved December 2, 2010. 
  16. Jump up ^ Lynch, John (1999). "Theory and External Validity" (PDF). Journal of the Academy of Marketing Science 27 (3): 367–76. 
  17. Jump up ^ Aronson, E., & Carlsmith, J.M. (1968). Experimentation in social psychology. In G. Lindzey & E. Aronson(Eds.), The Handbook of social psychology. (Vol. 2, pp. 1-79.) Reading, MA: Addison-Wesley.
  18. Jump up ^ Aronson, E., Wilson, T.D., & Brewer, m. (1998). Experimental methods. In D. Gilbert, S. Fiske, & G. Lindzey (Eds.), The handbook of social psychology. (4th ed., Vol. 1, pp. 99-142.) New York: Random House.
  19. Jump up ^ Aronson, E., Wilson, T. D., Akert, R. M., & Fehr, B. (2007). Social psychology. (4 ed.). Toronto, ON: Pearson Education.
  20. Jump up ^ Lynch, John (1982). "On the External Validity of Experiments in Consumer Research". Journal of Consumer Research 9 (3): 225–239. doi:10.1086/208919. Retrieved December 2, 2010. 
  21. Jump up ^ Hutchinson, J. Wesley; Kamakura, Wagner A.; Lynch, John G. (2000). "Unobserved Heterogeneity as an Alternative Explanation for "Reversal" Effects in Behavioral Research". Journal of Consumer Research 27 (3): 324–344. doi:10.1086/317588. 
  22. Jump up ^ Darley, J.M., & Batson, C.,D. (1973). From Jerusalem to Jericho: A study of situational and dispositional variables in helping behaviour. Journal of Personality and Social Psychology, 27, 100-108.
  23. Jump up ^ Darley, J.M., & Batson, C.,D. (1973). From Jerusalem to Jericho: A study of situational and dispositional variables in helping behaviour. Journal of Personality and Social Psychology, 27, 100-108.
  24. Jump up ^ Schwartz, S.H., & Gottlieb, A. (1976). Bystander reactions to a violent theft: Crime in Jerusalem. Journal of Personality and Social Psychology, 34, 1188-1199.
  25. Jump up ^ Latane, B., & Dabbs, J.M. (1975). Sex, group size, and helping in three cities. Sociometry, 38, 108-194.
  26. Jump up ^ Harrison, J.A., & Wells, R.B. (1991). Bystander effects on male helping behaviour: Social comparison and diffusion of responsibility. Representative Research in Social Psychology, 96, 187-192
  27. Jump up ^ Latane, B., & Darley, J.M. (1968). Group inhibition of bystander intervention. Journal of Personality and Social Psychology, 10, 215-221.
  28. Jump up ^ Hurley, D., & Allen, B.P. (1974). The effect of the number of people present in a nonemergency situation. Journal of Social Psychology, 92, 27-29.
  29. Jump up ^ Dipboye, Robert L.; Flanagan, Michael F. (1979). "Research Settings in Industrial and Organizational Psychology: Are Findings in the Field More Generalizable than the Laboratory". American Psychologist 34 (2): 141–150. doi:10.1037/0003-066x.34.2.141. 
  30. Jump up ^ Latane, B., & Darley, J.M. (1970). The unresponsive bystander: Why doesn't he help? Englewood Cliffs, NJ: Prentice Hall
Retrieved from "https://en.wikipedia.org/w/index.php?title=External_validity&oldid=703900735"
    


Internal validity

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Internal validity is a property of scientific studies which reflects the extent to which a causal conclusion based on a study is warranted. Such warrant is constituted by the extent to which a study minimizes systematic error (or 'bias').


Details[edit]

Inferences are said to possess internal validity if a causal relation between two variables is properly demonstrated.[1][2] A causal inference may be based on a relation when three criteria are satisfied:
  1. the "cause" precedes the "effect" in time (temporal precedence),
  2. the "cause" and the "effect" are related (covariation), and
  3. there are no plausible alternative explanations for the observed covariation (nonspuriousness).[2]
In scientific experimental settings, researchers often manipulate a variable (the independent variable) to see what effect it has on a second variable (the dependent variable).[3] For example, a researcher might, for different experimental groups, manipulate the dosage of a particular drug between groups to see what effect it has on health. In this example, the researcher wants to make a causal inference, namely, that different doses of the drug may be held responsible for observed changes or differences. When the researcher may confidently attribute the observed changes or differences in the dependent variable to the independent variable, and when he can rule out other explanations (or rival hypotheses), then his causal inference is said to be internally valid.[4]
In many cases, however, the magnitude of effects found in the dependent variable may not just depend on
  • variations in the independent variable,
  • the power of the instruments and statistical procedures used to measure and detect the effects, and
  • the choice of statistical methods (see: Statistical conclusion validity).
Rather, a number of variables or circumstances uncontrolled for (or uncontrollable) may lead to additional or alternative explanations (a) for the effects found and/or (b) for the magnitude of the effects found. Internal validity, therefore, is more a matter of degree than of either-or, and that is exactly why research designs other than true experiments may also yield results with a high degree of internal validity.
In order to allow for inferences with a high degree of internal validity, precautions may be taken during the design of the scientific study. As a rule of thumb, conclusions based on correlations or associations may only allow for lesser degrees of internal validity than conclusions drawn on the basis of direct manipulation of the independent variable. And, when viewed only from the perspective of Internal Validity, highly controlled true experimental designs (i.e. with random selection, random assignment to either the control or experimental groups, reliable instruments, reliable manipulation processes, and safeguards against confounding factors) may be the "gold standard" of scientific research. By contrast, however, the very strategies employed to control these factors may also limit the generalizability or External Validity of the findings.

Threats to internal validity[edit]

Ambiguous temporal precedence[edit]

Lack of clarity about which variable occurred first may yield confusion about which variable is the cause and which is the effect.

Confounding[edit]

A major threat to the validity of causal inferences is confounding: Changes in the dependent variable may rather be attributed to the existence or variations in the degree of a third variable which is related to the manipulated variable. Where spurious relationships cannot be ruled out, rival hypotheses to the original causal inference hypothesis of the researcher may be developed.

Selection bias[edit]

Selection bias refers to the problem that, at pre-test, differences between groups exist that may interact with the independent variable and thus be 'responsible' for the observed outcome. Researchers and participants bring to the experiment a myriad of characteristics, some learned and others inherent. For example, sex, weight, hair, eye, and skin color, personality, mental capabilities, and physical abilities, but also attitudes like motivation or willingness to participate.
During the selection step of the research study, if an unequal number of test subjects have similar subject-related variables there is a threat to the internal validity. For example, a researcher created two test groups, the experimental and the control groups. The subjects in both groups are not alike with regard to the independent variable but similar in one or more of the subject-related variables.

History[edit]

Events outside of the study/experiment or between repeated measures of the dependent variable may affect participants' responses to experimental procedures. Often, these are large scale events (natural disaster, political change, etc.) that affect participants' attitudes and behaviors such that it becomes impossible to determine whether any change on the dependent measures is due to the independent variable, or the historical event.

Maturation[edit]

Subjects change during the course of the experiment or even between measurements. For example, young children might mature and their ability to concentrate may change as they grow up. Both permanent changes, such as physical growth and temporary ones like fatigue, provide "natural" alternative explanations; thus, they may change the way a subject would react to the independent variable. So upon completion of the study, the researcher may not be able to determine if the cause of the discrepancy is due to time or the independent variable.

Repeated testing (also referred to as testing effects)[edit]

Repeatedly measuring the participants may lead to bias. Participants may remember the correct answers or may be conditioned to know that they are being tested. Repeatedly taking (the same or similar) intelligence tests usually leads to score gains, but instead of concluding that the underlying skills have changed for good, this threat to Internal Validity provides good rival hypotheses.

Instrument change (instrumentality)[edit]

The instrument used during the testing process can change the experiment. This also refers to observers being more concentrated or primed, or having unconsciously changed the criteria they use to make judgments. This can also be an issue with self-report measures given at different times. In this case the impact may be mitigated through the use of retrospective pretesting. If any instrumentation changes occur, the internal validity of the main conclusion is affected, as alternative explanations are readily available.

Regression toward the mean[edit]

Main article: Regression toward the mean
This type of error occurs when subjects are selected on the basis of extreme scores (one far away from the mean) during a test. For example, when children with the worst reading scores are selected to participate in a reading course, improvements at the end of the course might be due to regression toward the mean and not the course's effectiveness. If the children had been tested again before the course started, they would likely have obtained better scores anyway. Likewise, extreme outliers on individual scores are more likely to be captured in one instance of testing but will likely evolve into a more normal distribution with repeated testing.

Mortality/differential attrition[edit]

Main article: Survivorship bias
This error occurs if inferences are made on the basis of only those participants that have participated from the start to the end. However, participants may have dropped out of the study before completion, and maybe even due to the study or programme or experiment itself. For example, the percentage of group members having quit smoking at post-test was found much higher in a group having received a quit-smoking training program than in the control group. However, in the experimental group only 60% have completed the program. If this attrition is systematically related to any feature of the study, the administration of the independent variable, the instrumentation, or if dropping out leads to relevant bias between groups, a whole class of alternative explanations is possible that account for the observed differences.

Selection-maturation interaction[edit]

This occurs when the subject-related variables, color of hair, skin color, etc., and the time-related variables, age, physical size, etc., interact. If a discrepancy between the two groups occurs between the testing, the discrepancy may be due to the age differences in the age categories.

Diffusion[edit]

If treatment effects spread from treatment groups to control groups, a lack of differences between experimental and control groups may be observed. This does not mean, however, that the independent variable has no effect or that there is no relationship between dependent and independent variable.

Compensatory rivalry/resentful demoralization[edit]

Behavior in the control groups may alter as a result of the study. For example, control group members may work extra hard to see that expected superiority of the experimental group is not demonstrated. Again, this does not mean that the independent variable produced no effect or that there is no relationship between dependent and independent variable. Vice versa, changes in the dependent variable may only be affected due to a demoralized control group, working less hard or motivated, not due to the independent variable.

Experimenter bias[edit]

Experimenter bias occurs when the individuals who are conducting an experiment inadvertently affect the outcome by non-consciously behaving in different ways to members of control and experimental groups. It is possible to eliminate the possibility of experimenter bias through the use of double blind study designs, in which the experimenter is not aware of the condition to which a participant belongs.
For eight of these threats there exists the first letter mnemonic THIS MESS, which refers to the first letters of Testing (repeated testing), History, Instrument change, Statistical Regression toward the mean, Maturation, Experimental mortality, Selection and Selection Interaction.[5]

See also[edit]

References[edit]

  1. Jump up ^ Brewer, M. (2000). Research Design and Issues of Validity. In Reis, H. and Judd, C. (eds.) Handbook of Research Methods in Social and Personality Psychology. Cambridge:Cambridge University Press.
  2. ^ Jump up to: a b Shadish, W., Cook, T., and Campbell, D. (2002). Experimental and Quasi-Experimental Designs for Generilized Causal Inference Boston:Houghton Mifflin.
  3. Jump up ^ Levine, G. and Parkinson, S. (1994). Experimental Methods in Psychology. Hillsdale, NJ:Lawrence Erlbaum.
  4. Jump up ^ Liebert, R. M. & Liebert, L. L. (1995). Science and behavior: An introduction to methods of psychological research. Englewood Cliffs, NJ: Prentice Hall.
  5. Jump up ^ Wortman, P. M. (1983). "Evaluation research – A methodological perspective". Annual Review of Psychology 34: 223–260. doi:10.1146/annurev.ps.34.020183.001255. 

External links[edit]

Retrieved from "https://en.wikipedia.org/w/index.php?title=Internal_validity&oldid=686826005"
 


Ecological validity

From Wikipedia, the free encyclopedia
Jump to: navigation, search
For the ecological validity of a cue in perception, see ecological validity (perception).
In research, the ecological validity of a study means that the methods, materials and setting of the study must approximate the real-world that is being examined.[1] Unlike internal and external validity, ecological validity is not necessary to the overall validity of a study.[2][not specific enough to verify]

External validity versus ecological validity[edit]

Ecological validity is often confused with external validity (which deals with the ability of a study's results to generalize). While these forms of validity are closely related, they are independent—a study may possess external validity but not ecological validity, and vice versa.[1][2] For example, mock-jury research is designed to study how people might act if they were jurors during a trial, but many mock-jury studies simply provide written transcripts or summaries of trials, and do so in classroom or office settings. Such experiments do not approximate the actual look, feel and procedure of a real courtroom trial, and therefore lack ecological validity. However, the more important concern is that of external validity—if the results from such mock-jury studies generalize to real trials, then the research is valid as a whole, despite its ecological shortcomings. Nonetheless, improving the ecological validity of an experiment typically improves the external validity as well[citation needed].
The original meaning of 'ecological validity' defines it more narrowly as a property of stimuli in perceptual experiments. The popular use, broadly equivalent to 'realism', has overtaken it, at least in A Level Psychology circles. For the original (and some feel correct) use, see the entry on 'ecological validity - perception' and especially the paper by Hammond, 1998, which is referred to there. This can be accessed at: http://www.albany.edu/cpr/brunswik/notes/essay2.html . 'Representative design' captures the popular usage of ecological validity and can be used in its place.

See also[edit]

References[edit]

  1. ^ Jump up to: a b Brewer, M. (2000). Research Design and Issues of Validity. In Reis, H. and Judd, C. (eds) Handbook of Research Methods in Social and Personality Psychology. Cambridge:Cambridge University Press.
  2. ^ Jump up to: a b Shadish, W., Cook, T., and Campbell, D. (2002). Experimental and Quasi-Experimental Designs for Generalized Causal Inference Boston:Houghton Mifflin.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Ecological_validity&oldid=626797592"
 


Pharmacology

From Wikipedia, the free encyclopedia
Jump to: navigation, search
For the Wikipedia Manual of Style for Pharmacology, see WP:PHARMMOS


A variety of topics involved with pharmacology, including neuropharmacology, renal pharmacology, human metabolism, intracellular metabolism, and intracellular regulation
Pharmacology is the branch of medicine and biology concerned with the study of drug action,[1] where a drug can be broadly defined as any man-made, natural, or endogenous (from within body) molecule which exerts a biochemical and/or physiological effect on the cell, tissue, organ, or organism (sometimes the word pharmacon is used as a term to encompass these endogenous and exogenous bioactive species). More specifically, it is the study of the interactions that occur between a living organism and chemicals that affect normal or abnormal biochemical function. If substances have medicinal properties, they are considered pharmaceuticals.
The field encompasses drug composition and properties, synthesis and drug design, molecular and cellular mechanisms, organ/systems mechanisms, signal transduction/cellular communication, molecular diagnostics, interactions, toxicology, chemical biology, therapy, and medical applications and antipathogenic capabilities. The two main areas of pharmacology are pharmacodynamics and pharmacokinetics. The former studies the effects of the drug on biological systems, and the latter the effects of biological systems on the drug. In broad terms, pharmacodynamics discusses the chemicals with biological receptors, and pharmacokinetics discusses the absorption, distribution, metabolism, and excretion (ADME) of chemicals from the biological systems. Pharmacology is not synonymous with pharmacy and the two terms are frequently confused. Pharmacology, a biomedical science, deals with the research, discovery, and characterization of chemicals which show biological effects and the elucidation of cellular and organismal function in relation to these chemicals. In contrast, pharmacy, a health services profession, is concerned with application of the principles learned from pharmacology in its clinical settings; whether it be in a dispensing or clinical care role. In either field, the primary contrast between the two are their distinctions between direct-patient care, for pharmacy practice, and the science-oriented research field, driven by pharmacology.
The origins of clinical pharmacology date back to the Middle Ages in Avicenna's The Canon of Medicine, Peter of Spain's Commentary on Isaac, and John of St Amand's Commentary on the Antedotary of Nicholas.[2] Clinical pharmacology owes much of its foundation to the work of William Withering.[3] Pharmacology as a scientific discipline did not further advance until the mid-19th century amid the great biomedical resurgence of that period.[4] Before the second half of the nineteenth century, the remarkable potency and specificity of the actions of drugs such as morphine, quinine and digitalis were explained vaguely and with reference to extraordinary chemical powers and affinities to certain organs or tissues.[5] The first pharmacology department was set up by Rudolf Buchheim in 1847, in recognition of the need to understand how therapeutic drugs and poisons produced their effects.[4]
Early pharmacologists focused on natural substances, mainly plant extracts. Pharmacology developed in the 19th century as a biomedical science that applied the principles of scientific experimentation to therapeutic contexts.[6] Today Pharmacologists use genetics, molecular biology, chemistry, and other advanced tools to transform information about molecular mechanisms and targets into therapies directed against disease, defects or pathogens, and create methods for preventative care, diagnostics, and ultimately personalized medicine.


Divisions[edit]

The discipline of pharmacology can be divided into many sub disciplines each with a specific focus.

Clinical pharmacology[edit]

Clinical pharmacology is the basic science of pharmacology with an added focus on the application of pharmacological principles and methods in the medical clinic and towards patient care and outcomes.

Neuropharmacology[edit]

Neuropharmacology is the study of the effects of medication on central and peripheral nervous system functioning.

Psychopharmacology[edit]

Psychopharmacology is the study of the effects of medication on the psyche (psychology), observing changed behaviors of the body and mind, and how molecular events are manifest in a measurable behavioral form. This is similar to the closely related ethnopharmacology.

Cardiovascular pharmacology[edit]

Cardiovascular pharmacology is the study of the effects of medication on the heart.

Pharmacogenetics[edit]

Pharmacogenetics is clinical testing of genetic variation that gives rise to differing response to drugs.

Pharmacogenomics[edit]

Pharmacogenomics is the application of genomic technologies to drug discovery and further characterization of older drugs.
Identification of the genetic basis for polymorphic expression of a gene is done through intronic or exomic single-nucleotide polymorphisms (SNPs) which abolishes the need for different mechanisms for explaining the variability in drug metabolism. SNPs based variations in membrane receptors lead to multidrug resistance (MDR) and the drug–drug interactions. Even drug induced toxicity and many adverse effects can be explained by GWA studies. The multitude of SNPs help in understanding gene pharmacokinetic (PK) or pharmacodynamic (PD) pathways.[7]

Pharmacoepidemiology[edit]

Pharmacoepidemiology is the study of the effects of drugs in large numbers of people.

Systems Pharmacology[edit]

Systems pharmacology is the application of systems biology principles to the field of pharmacology.

Toxicology[edit]

Toxicology is the study of the adverse effects, molecular targets, and characterization of drugs or any chemical substance in excess (including those beneficial in lower doses).

Theoretical pharmacology[edit]

Theoretical pharmacology is a relatively new and rapidly expanding field of research activity in which many of the techniques of computational chemistry, in particular computational quantum chemistry and the method of molecular mechanics, are proving to be of great value. Theoretical pharmacologists aim at rationalizing the relation between the activity of a particular drug, as observed experimentally, and its structural features as derived from computer experiments. They aim to find structure—activity relations. Furthermore, on the basis of the structure of a given organic molecule, the theoretical pharmacologist aims at predicting the biological activity of new drugs that are of the same general type as existing drugs. More ambitiously, he aims to predict entirely new classes of drugs, tailor-made for specific purposes.

Posology[edit]

Posology is the study of how medicines are dosed. It also depends upon various factors including age, climate, weight, sex, and time of administration. It is derived from the Greek words posos meaning how much and logos meaning science.

Pharmacognosy[edit]

Pharmacognosy is a branch of pharmacology dealing especially with the composition, use, and development of medicinal substances of biological origin and especially medicinal substances obtained from plants.

Behavioral pharmacology[edit]

Behavioral pharmacology, also referred to as psychopharmacology or ethopharmacology (not to be confused with Ethnopharmacology), is an interdisciplinary field which studies behavioral effects of psychoactive drugs. It incorporates approaches and techniques from neuropharmacology, animal behavior and behavioral neuroscience, and is interested in the behavioral and neurobiological mechanisms of action of psychoactive drugs. Another goal of behavioral pharmacology is to develop animal behavioral models to screen chemical compounds with therapeutic potentials. People in this field (called behavioral pharmacologists) typically use small animals (e.g. rodents) to study psychotherapeutic drugs such as antipsychotics, antidepressants and anxiolytics, and drugs of abuse such as nicotine, cocaine, methamphetamine, etc. study of drugs which affect behavior. Ethopharmacology is a term which has been in use since the 1960s[8] and derives from the Greek word "ethos" meaning character and "pharmacology" the study of drug actions and mechanism.

Environmental pharmacology[edit]

Environmental pharmacology is a new discipline.[9] Focus is being given to understand gene–environment interaction, drug-environment interaction and toxin-environment interaction. There is a close collaboration between environmental science and medicine in addressing these issues, as healthcare itself can be a cause of environmental damage or remediation. Human health and ecology are intimately related. Demand for more pharmaceutical products may place the public at risk through the destruction of species. The entry of chemicals and drugs into the aquatic ecosystem is a more serious concern today. In addition, the production of some illegal drugs pollutes drinking water supply by releasing carcinogens.[10] This field is intimately linked with Public Health fields.

Dental pharmacology[edit]

Dental pharmacology relates to the study of drugs commonly used in the treatment of dental disease.[11]

Scientific background[edit]

The study of chemicals requires intimate knowledge of the biological system affected. With the knowledge of cell biology and biochemistry increasing, the field of pharmacology has also changed substantially. It has become possible, through molecular analysis of receptors, to design chemicals that act on specific cellular signaling or metabolic pathways by affecting sites directly on cell-surface receptors (which modulate and mediate cellular signaling pathways controlling cellular function).
A chemical has, from the pharmacological point-of-view, various properties. Pharmacokinetics describes the effect of the body on the chemical (e.g. half-life and volume of distribution), and pharmacodynamics describes the chemical's effect on the body (desired or toxic).
When describing the pharmacokinetic properties of the chemical that is the active ingredient or active pharmaceutical ingredient (API), pharmacologists are often interested in L-ADME:
  • Liberation – How is the API disintegrated (for solid oral forms (breaking down into smaller particles)), dispersed, or dissolved from the medication?
  • Absorption – How is the API absorbed (through the skin, the intestine, the oral mucosa)?
  • Distribution – How does the API spread through the organism?
  • Metabolism – Is the API converted chemically inside the body, and into which substances. Are these active (as well)? Could they be toxic?
  • Excretion – How is the API excreted (through the bile, urine, breath, skin)?
Medication is said to have a narrow or wide therapeutic index or therapeutic window. This describes the ratio of desired effect to toxic effect. A compound with a narrow therapeutic index (close to one) exerts its desired effect at a dose close to its toxic dose. A compound with a wide therapeutic index (greater than five) exerts its desired effect at a dose substantially below its toxic dose. Those with a narrow margin are more difficult to dose and administer, and may require therapeutic drug monitoring (examples are warfarin, some antiepileptics, aminoglycoside antibiotics). Most anti-cancer drugs have a narrow therapeutic margin: toxic side-effects are almost always encountered at doses used to kill tumors.

Medicine development and safety testing[edit]

Development of medication is a vital concern to medicine, but also has strong economical and political implications. To protect the consumer and prevent abuse, many governments regulate the manufacture, sale, and administration of medication. In the United States, the main body that regulates pharmaceuticals is the Food and Drug Administration and they enforce standards set by the United States Pharmacopoeia. In the European Union, the main body that regulates pharmaceuticals is the EMEA and they enforce standards set by the European Pharmacopoeia.
The metabolic stability and the reactivity of a library of candidate drug compounds have to be assessed for drug metabolism and toxicological studies. Many methods have been proposed for quantitative predictions in drug metabolism; one example of a recent computational method is SPORCalc.[12] If the chemical structure of a medicinal compound is altered slightly, this could slightly or dramatically alter the medicinal properties of the compound depending on the level of alteration as it relates to the structural composition of the substrate or receptor site on which it exerts its medicinal effect, a concept referred to as the structural activity relationship (SAR). This means that when a useful activity has been identified, chemists will make many similar compounds called analogues, in an attempt to maximize the desired medicinal effect(s) of the compound. This development phase can take anywhere from a few years to a decade or more and is very expensive.[13]
These new analogues need to be developed. It needs to be determined how safe the medicine is for human consumption, its stability in the human body and the best form for delivery to the desired organ system, like tablet or aerosol. After extensive testing, which can take up to 6 years, the new medicine is ready for marketing and selling.[13]
As a result of the long time required to develop analogues and test a new medicine and the fact that of every 5000 potential new medicines typically only one will ever reach the open market, this is an expensive way of doing things, often costing over 1 billion dollars. To recoup this outlay pharmaceutical companies may do a number of things:[13]
  • Carefully research the demand for their potential new product before spending an outlay of company funds.[13]
  • Obtain a patent on the new medicine preventing other companies from producing that medicine for a certain allocation of time.[13]

Drug legislation and safety[edit]

In the United States, the Food and Drug Administration (FDA) is responsible for creating guidelines for the approval and use of drugs. The FDA requires that all approved drugs fulfill two requirements:
  1. The drug must be found to be effective against the disease for which it is seeking approval (where 'effective' means only that the drug performed better than placebo or competitors in at least two trials).
  2. The drug must meet safety criteria by being subject to animal and controlled human testing.
Gaining FDA approval usually takes several years to attain. Testing done on animals must be extensive and must include several species to help in the evaluation of both the effectiveness and toxicity of the drug. The dosage of any drug approved for use is intended to fall within a range in which the drug produces a therapeutic effect or desired outcome.[14]
The safety and effectiveness of prescription drugs in the U.S. is regulated by the federal Prescription Drug Marketing Act of 1987.
The Medicines and Healthcare products Regulatory Agency (MHRA) has a similar role in the UK.

Education[edit]

Students of pharmacology are trained as biomedical scientists, studying the effects of drugs on living organisms. This can lead to new drug discoveries, as well as a better understanding of the way in which the human body works.
Students of pharmacology must have detailed working knowledge of aspects in physiology, pathology and chemistry. During a typical degree they will cover areas such as (but not limited to) biochemistry, cell biology, basic physiology, genetics & the Central Dogma, medical microbiology, neuroscience, and depending on the department's interests, bio-organic chemistry and/or chemical biology.
Modern Pharmacology is highly interdisciplinary. Graduate programs accept students from most biological and chemical backgrounds. With the increasing drive towards biophysical and computational research to describe systems, pharmacologists may even consider themselves mainly physical scientists. In many instances, Analytical Chemistry is closely related to the studies and needs of pharmacological research. Therefore, many institutions will include pharmacology under a Chemistry or Biochemistry Department, especially if a separate Pharmacology Dept. does not exist. What makes an institutional department independent of another, or exist in the first place, is usually an artifact of historical times.
Whereas a pharmacy student will eventually work in a pharmacy dispensing medications, a pharmacologist will typically work within a laboratory setting. Careers for a pharmacologist include academic positions (medical and non-medical), governmental positions, private industrial positions, science writing, scientific patents and law, consultation, biotech and pharmaceutical employment, the alcohol industry, food industry, forensics/law enforcement, public health, and environmental/ecological sciences.

See also[edit]

Notes and references[edit]

  1. Jump up ^ Vallance P, Smart TG (January 2006). "The future of pharmacology". British Journal of Pharmacology. 147 Suppl 1 (S1): S304–7. doi:10.1038/sj.bjp.0706454. PMC 1760753. PMID 16402118. 
  2. Jump up ^ Brater DC, Daly WJ (May 2000). "Clinical pharmacology in the Middle Ages: principles that presage the 21st century". Clin. Pharmacol. Ther. 67 (5): 447–50. doi:10.1067/mcp.2000.106465. PMID 10824622. 
  3. Jump up ^ Mannfred A. Hollinger (2003)."Introduction to pharmacology". CRC Press. p.4. ISBN 0-415-28033-8
  4. ^ Jump up to: a b Rang HP (January 2006). "The receptor concept: pharmacology's big idea". Br. J. Pharmacol. 147 Suppl 1 (S1): S9–16. doi:10.1038/sj.bjp.0706457. PMC 1760743. PMID 16402126. 
  5. Jump up ^ Maehle AH, Prüll CR, Halliwell RF (August 2002). "The emergence of the drug receptor theory". Nat Rev Drug Discov 1 (8): 637–41. doi:10.1038/nrd875. PMID 12402503. 
  6. Jump up ^ Rang, H.P.; M.M. Dale; J.M. Ritter; R.J. Flower (2007). Pharmacology. China: Elsevier. ISBN 0-443-06911-5. 
  7. Jump up ^ Fareed M., Afzal M (2013). "Single nucleotide polymorphism in genome-wide association of human population: A tool for broad spectrum service". Egyptian Journal of Medical Human Genetics 14 (2): 123–134. doi:10.1016/j.ejmhg.2012.08.001. 
  8. Jump up ^ Krsiak, M (1991). "Ethopharmacology: A historical perspective". Neuroscience and biobehavioral reviews 15 (4): 439–45. doi:10.1016/s0149-7634(05)80124-1. PMID 1792005. 
  9. Jump up ^ Rahman, SZ; Khan, RA (Dec 2006). "Environmental pharmacology: A new discipline". Indian J Pharmacol. 38 (4): 229–30. doi:10.4103/0253-7613.27017. 
  10. Jump up ^ Sue Ruhoy Ilene, Daughton Christian G (2008). "Beyond the medicine cabinet: An analysis of where and why medications accumulate". Environment International 34 (8): 1157–1169. doi:10.1016/j.envint.2008.05.002. 
  11. Jump up ^ "Dental Pharmacology". nba.uth.tmc.edu. Texas Medical Center. Retrieved 22 May 2015. 
  12. Jump up ^ James Smith; Viktor Stein (2009). "SPORCalc: A development of a database analysis that provides putative metabolic enzyme reactions for ligand-based drug design". Computational Biology and Chemistry 33 (2): 149–159. doi:10.1016/j.compbiolchem.2008.11.002. PMID 19157988. 
  13. ^ Jump up to: a b c d e Newton, David; Alasdair Thorpe; Chris Otter (2004). Revise A2 Chemistry. Heinemann Educational Publishers. p. 1. ISBN 0-435-58347-6. 
  14. Jump up ^ Nagle, Hinter; Barbara Nagle (2005). Pharmacology: An Introduction. Boston: McGraw Hill. ISBN 0-07-312275-0. 

External links[edit]

Wikimedia Commons has media related to Pharmacology.
Authority control
Retrieved from "https://en.wikipedia.org/w/index.php?title=Pharmacology&oldid=705567345"

Navigation menu

 


Legal research

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Legal research is "the process of identifying and retrieving information necessary to support legal decision-making. In its broadest sense, legal research includes each step of a course of action that begins with an analysis of the facts of a problem and concludes with the application and communication of the results of the investigation."[1]
The processes of legal research vary according to the country and the legal system involved. However, legal research generally involves tasks such as: 1) finding primary sources of law, or primary authority, in a given jurisdiction (cases, statutes, regulations, etc.); 2) searching secondary authority (for example, law reviews, legal dictionaries, legal treatises, and legal encyclopedias such as American Jurisprudence and Corpus Juris Secundum), for background information about a legal topic; and 3) searching non-legal sources for investigative or supporting information.
Legal research is performed by anyone with a need for legal information, including lawyers, law librarians, and paralegals. Sources of legal information range from printed books, to free legal research websites (like Cornell Law School’s Legal Information Institute, Findlaw.com, Martindale Hubbell, Lawyer.com, Lawyers.com, CanLII) and information portals to fee database vendors such as Wolters Kluwer, Chancery Law Chronicles,[2] LexisNexis, Westlaw, and Bloomberg Law. Law libraries around the world provide research services to help their patrons find the legal information they need in law schools, law firms and other research environments. Many law libraries and institutions provide free access to legal information on the web, either individually or via collective action, such as with the Free Access to Law Movement.


Databases and software[edit]

An Australian team created AustLII, a database collecting all primary sources from each Australian jurisdiction and some secondary sources, all freely available. It has now been replicated in many countries as BAILII, CanLII, WorldLII, etc.

Third-Party Legal Research Providers[edit]

Legal research is known to take much time and effort, and access to online legal research databases such as LexisNexis and Westlaw can be costly. Consequently, law firms and other practitioners may turn to third-party legal research providers to outsource their legal research needs.
On August 5, 2008, the American Bar Association, Standing Committee on Ethics and Professional Responsibility, issued Formal Opinion 08-451, entitled "Lawyer’s Obligations When Outsourcing Legal and Nonlegal Support Services."[3] Among other things, this Opinion expressly acknowledges:
Outsourcing affords lawyers the ability to reduce their costs and often the cost to the client to the extent that the individuals or entities providing the outsourced services can do so at lower rates than the lawyer’s own staff. In addition, the availability of lawyers and nonlawyers to perform discrete tasks may, in some circumstances, allow for the provision of labor-intensive legal services by lawyers who do not otherwise maintain the needed human resources on an ongoing basis. A small firm might not regularly employ the lawyers and legal assistants required to handle a large, discovery-intensive litigation effectively. Outsourcing, however, can enable that firm to represent a client in such a matter effectively and efficiently, by engaging additional lawyers to conduct depositions or to review and analyze documents, together with a temporary staff of legal assistants to provide infrastructural support.
  • * * *
There is no unique blueprint for the provision of competent legal services. Different lawyers may perform the same tasks through different means, all with the necessary “legal knowledge, skill, thoroughness and preparation.” One lawyer may choose to do all of the work herself. Another may delegate tasks to a team of subordinate lawyers and nonlegal staff. Others may decide to outsource tasks to independent service providers that are not within their direct control. Rule 1.1 does not require that tasks be accomplished in any special way. The rule requires only that the lawyer who is responsible to the client satisfies her obligation to render legal services competently.[4]
The Standing Committee on Ethics and Professional Responsibility thus concluded that "[t]here is nothing unethical about a lawyer outsourcing legal and nonlegal services, provided the outsourcing lawyer renders legal services to the client with the 'legal knowledge, skill, thoroughness and preparation reasonably necessary for the representation,' as required by Rule 1.1."[5]

See also[edit]

External links[edit]

References[edit]

Library resources about
Legal research
  1. Jump up ^ J. Myron Jacobstein and Roy M. Mersky, Fundamentals of Legal Research, 8th ed. (Foundation Press, 2002) p. 1.
  2. Jump up ^ clcbd.org
  3. Jump up ^ http://legalresearchexperts.com/outsourcing.html#fn1text
  4. Jump up ^ http://legalresearchexperts.com/outsourcing.html#fn1text
  5. Jump up ^ http://legalresearchexperts.com/outsourcing.html#fn1text
Retrieved from "https://en.wikipedia.org/w/index.php?title=Legal_research&oldid=676546467"
 


Laboratory

From Wikipedia, the free encyclopedia
Jump to: navigation, search
For other uses, see Lab (disambiguation) and Laboratory (disambiguation).


A medical laboratory run by the Graduate Institute of Cancer Biology of China Medical University (Taiwan)


Molecular Biology Technics Laboratory at Faculty of Biology of Adam Mickiewicz University in Poznan


A workbench in a chemistry laboratory


The Schuster Laboratory, University of Manchester (a physics laboratory)
A laboratory (/ləˈbɒrətəri/ or /ˈlæbərətɔːri/; informally, lab) is a facility that provides controlled conditions in which scientific or technological research, experiments, and measurement may be performed.
Laboratories used for scientific research take many forms because of the differing requirements of specialists in the various fields of science and engineering. A physics laboratory might contain a particle accelerator or vacuum chamber, while a metallurgy laboratory could have apparatus for casting or refining metals or for testing their strength. A chemist or biologist might use a wet laboratory, while a psychologist's laboratory might be a room with one-way mirrors and hidden cameras in which to observe behavior. In some laboratories, such as those commonly used by computer scientists, computers (sometimes supercomputers) are used for either simulations or the analysis of data collected elsewhere. Scientists in other fields will use still other types of laboratories. Engineers use laboratories as well to design, build, and test technological devices.
Scientific laboratories can be found in schools and universities, in industry, in government or military facilities, and even aboard ships and spacecraft.


History[edit]

Early instances of "laboratories" recorded in English involved alchemy and the preparation of medicines.[1]

Techniques[edit]

Laboratory techniques are the sum of procedures used on natural sciences such as chemistry, biology, physics in order to conduct an experiment, all of them follow scientific method; while some of them involves the use of complex laboratory equipment from laboratory glassware to electrical devices others require such specific or expensive supplies.

Equipment[edit]



Three beakers, an Erlenmeyer flask, a graduated cylinder and a volumetric flask
Laboratory equipment refers to the various tools and equipment used by scientists working in a laboratory:
The classical equipment includes tools such as Bunsen burners and microscopes as well as specialty equipment such as operant conditioning chambers, spectrophotometers and calorimeters.
Chemical laboratories:
Molecular biology laboratories + Life science laboratories:
Laboratory equipment is generally used to either perform an experiment or to take measurements and gather data. Larger or more sophisticated equipment is generally called a scientific instrument. Both laboratory equipment and scientific instruments are increasingly being designed and shared using open hardware principles.[2] [3]
open source labs use open source scientific hardware.[4][5]

Specialized types[edit]

The title of laboratory is also used for certain other facilities where the processes or equipment used are similar to those in scientific laboratories. These notably include:

Safety[edit]

Main article: Laboratory safety


An eyewash station in a laboratory.
In some laboratories, the conditions are no more dangerous than in any other room. In many labs, though, hazards are present. Laboratory hazards are as varied as the subjects of study in laboratories, and might include poisons; infectious agents; flammable, explosive, or radioactive materials; moving machinery; extreme temperatures; lasers, strong magnetic fields or high voltage. In laboratories where dangerous conditions might exist, safety precautions are important. Rules exist to minimize the individual's risk, and safety equipment is used to protect the lab user from injury or to assist in responding to an emergency.
The Occupational Safety and Health Administration (OSHA) in the United States, recognizing the unique characteristics of the laboratory workplace, has tailored a standard for occupational exposure to hazardous chemicals in laboratories. This standard is often referred to as the "Laboratory Standard". Under this standard, a laboratory is required to produce a Chemical Hygiene Plan (CHP) which addresses the specific hazards found in its location, and its approach to them.
In determining the proper Chemical Hygiene Plan for a particular business or laboratory, it is necessary to understand the requirements of the standard, evaluation of the current safety, health and environmental practices and assessment of the hazards. The CHP must be reviewed annually. Many schools and businesses employ safety, health, and environmental specialists, such as a Chemical Hygiene Officer (CHO) to develop, manage, and evaluate their CHP. Additionally, third party review is also used to provide an objective "outside view" which provides a fresh look at areas and problems that may be taken for granted or overlooked due to habit.
Inspections and audits like also be conducted on a regular basis to assess hazards due to chemical handling and storage, electrical equipment, biohazards, hazardous waste management, chemical waste, housekeeping and emergency preparedness, radiation safety, ventilation as well as respiratory testing and indoor air quality. An important element of such audits is the review of regulatory compliance and the training of individuals who have access to and/or work in the laboratory. Training is critical to the ongoing safe operation of the laboratory facility. Educators, staff and management must be engaged in working to reduce the likelihood of accidents, injuries and potential litigation. Efforts are made to ensure laboratory safety videos are both relevant and engaging.[6]

See also[edit]

References[edit]

  1. Jump up ^ "laboratory". Oxford English Dictionary (3rd ed.). Oxford University Press. September 2005.  (Subscription or UK public library membership required.): "Originally: a room or building for the practice of alchemy and the preparation of medicines. Later: one equipped for carrying out scientific experiments or procedures, esp. for the purposes of research, teaching, or analysis; (also) one in which chemicals or drugs are manufactured."
  2. Jump up ^ Pearce, J.M., 2014. Laboratory equipment: Cut costs with open-source hardware. Nature 505, 618. doi:10.1038/505618d
  3. Jump up ^ Baden, T., Chagas, A. M., Gage, G., Marzullo, T., Prieto-Godino, L. L., & Euler, T. (2015). Open Labware: 3-D Printing Your Own Lab Equipment. PLOS Biology, 13(3). DOI: 10.1371/journal.pbio.1002086 http://journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1002086
  4. Jump up ^ Joshua M. Pearce,Open-Source Lab:How to Build Your Own Hardware and Reduce Research Costs, Elsevier, 2014. ISBN 9780124104624
  5. Jump up ^ Joshua M. Pearce, “Building Research Equipment with Free, Open-Source Hardware.” Science 337 (6100): 1303–1304 (2012).
  6. Jump up ^ Michael L. Matson, Jeffrey P. Fitzgerald, Shirley Lin (October 1, 2007). "Creating Customized, Relevant, and Engaging Laboratory Safety Videos". Journal of Chemical Education 84 (10): 1727. Bibcode:2007JChEd..84.1727M. doi:10.1021/ed084p1727. Retrieved 22 February 2013. 

External links[edit]

Authority control
Retrieved from "https://en.wikipedia.org/w/index.php?title=Laboratory&oldid=701954974"




THE CONCEPT THAT ORGANISES HOW  ASPECTS OF PERSONALITY AND INTELLGENCE ARE UNDERSTOOD  FOR HEALTHCARE PROVISIION AND HEALTH CARE SYSTEM AND MEDICAL SCIENCE FOR THE CARE OF  THE AFFECTED

 LOGICAL VALIDITY OF CONSERVATORSHIP ORDERS  FOR ELDERLY OR OLDER PEOPLE AND ADULT PSYCHIATRY  REGARRDS  TO THE LAW OF TRESPASS;THE LAW OF NUISANCE;THE LAW OF HINDRANCES  EITHER IN FORM OF  FREE MOVEMENTS OF PERSONS AND  SERVICES  AND OR BUSINESS

DEPRESSION  SCALE OF CONSERVATORSHIP ORDERS FOR ELDERLY OR OLDER PEOPLE AND ADULT PSYCHIATRY  IN SOCIAL CONSTRUCT MISSES  CONTENT VALIDITY:

AS A HEALTH RESEARCH ER PARTICIPANT HEALTH PRACTITIONER WORKER  OF THE WORLD HEALTH ORGANISATION BEING THE REGULATORS OF HEALTH PROFESSION UNDER THE MEMBERSHIP OF MEMBER STATES AND THE WORLD ASSEMBLY  FROM 1991 TO 1998 AS A TRANSLATIONAL RESEARCHER IN  THREE HEALTH FACILITY IN FRANKFURT AM MAIN GERMANY IN THE EUROPEAN UNION.THE  PROCEDURAL PROCESSES TO WRITE THIS LITERARY WORK  AND LETTERS COMPOSITION WAS MADE POSSIBLE IN MY EMPLOYMENT CONTRACT AS A TRANSLATIONAL  RESEARCHER FROM 1993 TO 1998 SAID ALSO TO BE SEMANTIC AS GERIATRIC NURSING  IN SOME HEALTH FACILITY AND NURSING IN ANOTHER AND ALSO THE PUBLIC HEALTH SCHOOL EDUCATION AND CERTIFICATION UNDER THE REGULATION OF THE  WORLD HEALTH  ASSEMBLY AND THE WORLD HEALTH ORGANISATION  AND THE EUROPEAN MEDICINE AGENCY.

I HAD ARRIVED EUROPE FOR THE FIRST TIME ON BOARD  AN AEROPLANE ORGANISATION REGISTERED IN THE SWITZERLAND TO THE CITY OF GENEVA AND ON TO THE CITY OF ZURICH BEFORE TRAVELLING TO FRANKFURT AM MAIN GERMANY IN THE EUROPEAN UNION ON  THE MORNING  OF THE 17TH DAY OF JANUARY 1990 FROM LAGOS NIGERIA WEST COAST OF AFRICA WERE I WAS BORN IN THE YEAR 1963 OF THE DAY AND MONTH OF 20TH SEPTEMBER.

 

 

 

 

 

 

 

 

 

 

 

LITERARY AND LAWS

EFFECTS AND WELLBEING

COURT ORDERS,LIVING WELL AND HEALTH

PARLIAMENTARY OPINIONS

IMMIGRATION LAWS AND VISA

SITUATIONS AND HEALTH CARE PRACTICE

UNHAPPY MIND AND MONEY MATTERS

UNHAPPY MIND AND PSYCHIATRIC ILLNESSS

PSYCHIATRIC  DIAGNOSIS,THERAPEUTIC MEASURES AND SUBSTANTIATION OF DIAGNOSIS

FROM AN ACCUSATION ATTRIBUTE OR PROVOCATIONAL TENDENCIES OR NEITHER OF SORTS,THIS ACADEMIC WRITING IS PUBLISHED UNDER THE TERM  ACADEMIC WRITING

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

CORE PAPERS AND EXPANSIVE SHEETS

LAW SUBJECT GUIDE

 













 

 

 

 

 

 

 

 

 

 

 

 

ABOUT THE WRITER  OF  THIS ACADEMIC WRITING

                                                                                                 

 

 

 

NAME .MR FELIX ATI JOHN

DATE OF BIRTH,20,09,1963

PLACE OF BIRTH,LAGOS ISLAND NIGERIA

MARITAL STATUS – SINGLE

CHIKDREN  -  NONE AS AT THE TIME OF THIS PUBLICATION

ENGLISH LEGAL SYSTEM CHILD GUARDIANSHIP  IN 1963 –  MR  DAVID  ATI-JOHN

PROFESSIONAL CERTIFICATION.

GERONTOLOGY

ENGLISH AND EUROPEAN LEGAL SYSTEM

TRANSLATIONAL MEDICINE RESEARCHER

IN RESPECT OF THE HEALTH PROFESSION.

HEALTH PROFESSIONAL EXPERIENCE.

PRACTITIONER RESEARCH

MR.FELIX ATI-JOHN IS A QUALIFIED GERONTOLOGIST FORMERLY  A TRANSLATIONAL MEDICINE RESEARCHER   AT THE SAINT KATHARINEN HOSPITAL 1993 TO 1996,SECKBACH FRANKFURT AM MAIN GERMANY IN THE EUROPEAN UNION AND ALSO AT THE MAYOR GRAEF HOUSE  FRANKFURTER ORGANISATION FOR  OLDER AND HANDICAP PEOPLE HELP EV FRANKFURT AM MAIN GERMANY IN THE EUROPEAN UNION AND AT THE DEPARTMENT OF PSYCHIATRY,JOHANN WOLFGANG GOETHE UNIVERSITY TEACHING HOSPITAL FRANKFURT AM MAIN IN THE EUROPEAN UNION..MR.FELIX ATI-JOHN ALSO WORKED SHORTLY AT  THE REHA DEPARTMENT HUFELAND HOUSE SECKBACH  IN 1998 AND  AT THE JOHANNA  KIRCHNER HOUSE-TWICE INTO AT THE INSOLVENT COMPANY OF KERSTIN HAIN  GROSS KARBEN IN 1999 AND ALSO AT  THE GESS MEDICAL FRANKFURT AM MAIN GERMANY  NOT TO FORGET THE ERSCHERSHEIMER STREET MEDICAL COMPANY FRANKFURT AM MAIN GERMANY IN THE EUROPEAN UNION.

THIS WORK IS TITLED  CONSERVATORSHIP LAWS IN ELDERLY OR OLDER PEOPLE HELP AND ADULT PSYCHIATRY BUT THIS TITLE OF THIS RESEARCH PAPER AND ITS CONTENT DOES NOT AND IS  NOT INTENDED TO UNDERMINE THE LAW OF REAL PROPERTY AS WELL AS THE LAW OF INTELLECTUAL PROPERTY AND ALSO  OF TANGIBLE AND INTANGIBLE LEGAL DEFINITION OF REAL PROPERTY.

OF BOTH TANGIBLE AND INTANGIBLE DEFINITIONS AND EXPLANATIONS,ORDERS AND ATTACHMENTS,RIGHT TO QUIET ENJOYMENT AND FINANCIAL ACTIVITY

 

MR FELIX ATI-JOHN  ATTENDED THE PUBLIC  HEALTH SCHOOL HUFELAND HOUSE FRANKFURT SECKBACH,GERMANY IN THE EUROPEAN UNION FROM 1991 TO 1993 WITH CORE PAPERS AND ITS EXPANSIVE SHEETS

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Posted by at

No comments:

Post a Comment