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Reactivity (psychology)
Reactivity is a phenomenon that occurs when individuals alter their performance or behavior due to the awareness that they are being observed. The change may be positive or negative, and depends on the situation. It is a significant threat to a research study's external validity and is typically controlled for using blind experiment designs. There are several forms of reactivity. The Hawthorne effect occurs when research study participants know they are being studied and alter their performance because of the attention they receive from the experimenters. The John Henry effect, a specific form of Hawthorne effect, occurs when the participants in the control group alter their behavior out of awareness that they are in the control group. Reactivity is not limited to changes in behaviour in relation to being merely observed; it can also refer to situations where individuals alter their behavior to conform to the expectations of the observer. An experimenter effect occurs when t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
External Validity
External validity is the validity of applying the conclusions of a scientific study outside the context of that study. In other words, it is the extent to which the results of a study can be generalized to and across other situations, people, stimuli, and times.Aronson, E., Wilson, T. D., Akert, R. M., & Fehr, B. (2007). Social psychology. (4 ed.). Toronto, ON: Pearson Education. In contrast, internal validity is the validity of conclusions drawn ''within'' the context of a particular study. Because general conclusions are almost always a goal in research, external validity is an important property of any study. Mathematical analysis of external validity concerns a determination of whether generalization across heterogeneous populations is feasible, and devising statistical and computational methods that produce valid generalizations. Threats "A threat to external validity is an explanation of how you might be wrong in making a generalization from the findings of a particular study ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimental Control
A scientific control is an experiment or observation designed to minimize the effects of variables other than the independent variable (i.e. confounding variables). This increases the reliability of the results, often through a comparison between control measurements and the other measurements. Scientific controls are a part of the scientific method. Controlled experiments Controls eliminate alternate explanations of experimental results, especially experimental errors and experimenter bias. Many controls are specific to the type of experiment being performed, as in the molecular markers used in SDS-PAGE experiments, and may simply have the purpose of ensuring that the equipment is working properly. The selection and use of proper controls to ensure that experimental results are valid (for example, absence of confounding variables) can be very difficult. Control measurements may also be used for other purposes: for example, a measurement of a microphone's background noise in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blind Experiment
In a blind or blinded experiment, information which may influence the participants of the experiment is withheld until after the experiment is complete. Good blinding can reduce or eliminate experimental biases that arise from a participants' expectations, observer's effect on the participants, observer bias, confirmation bias, and other sources. A blind can be imposed on any participant of an experiment, including subjects, researchers, technicians, data analysts, and evaluators. In some cases, while blinding would be useful, it is impossible or unethical. For example, it is not possible to blind a patient to their treatment in a physical therapy intervention. A good clinical protocol ensures that blinding is as effective as possible within ethical and practical constraints. During the course of an experiment, a participant becomes unblinded if they deduce or otherwise obtain information that has been masked to them. For example, a patient who experiences a side effect may corr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawthorne Effect
The Hawthorne effect is a type of reactivity in which individuals modify an aspect of their behavior in response to their awareness of being observed. The effect was discovered in the context of research conducted at the Hawthorne Western Electric plant; however, some scholars feel the descriptions are apocryphal. The original research involved workers who made electrical relays at the Hawthorne Works, a Western Electric plant in Cicero, Illinois. Between 1924 and 1927, the lighting study was conducted. Workers experienced a series of lighting changes in which productivity was said to increase with almost any change in the lighting. This turned out ''not'' to be true. In the study that was associated with Elton Mayo, which ran from 1928 to 1932, a series of changes in work structure were implemented (e.g., changes in rest periods) in a group of five women. However, this was a methodologically poor, uncontrolled study that did not permit any firm conclusions to be drawn. One of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Henry Effect
The John Henry effect is an experimental bias introduced into social experiments by reactive behavior by the control group. In a controlled social experiment if a control is aware of their status as members of the control group and is able to compare their performance with that of the treatment group, members of the control group may actively work harder to overcome the "disadvantage" of being in the control group. For example, if in an educational trial where the school classes who are in the treatment receive an extra support teacher, students who are in the control group may be induced to work harder to overcome that disadvantage. The term was first used by Gary Saretsky (1972) to describe the behavior of John Henry, a legendary American steel driver in the 1870s who, when he heard his output was being compared with that of a steam drill, worked so hard to outperform the machine that he died in the process. See also * Hawthorne effect * Reactivity (psychology) * John Henryi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Experimenter Effect
The observer-expectancy effect (also called the experimenter-expectancy effect, expectancy bias, observer effect, or experimenter effect) is a form of reactivity in which a researcher's cognitive bias causes them to subconsciously influence the participants of an experiment. Confirmation bias can lead to the experimenter interpreting results incorrectly because of the tendency to look for information that conforms to their hypothesis, and overlook information that argues against it. It is a significant threat to a study's internal validity, and is therefore typically controlled using a double-blind experimental design. It may include conscious or unconscious influences on subject behavior including creation of demand characteristics that influence subjects, and altered or selective recording of experimental results themselves. Overview The experimenter may introduce cognitive bias into a study in several ways. In what is called the observer-expectancy effect, the experimen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pygmalion Effect
The Pygmalion effect, or Rosenthal effect, is a psychological phenomenon in which high expectations lead to improved performance in a given area. The effect is named for the Greek myth of Pygmalion, the sculptor who fell so much in love with the perfectly beautiful statue he created that the statue came to life. The psychologists Robert Rosenthal and Lenore Jacobson, in their book ''Pygmalion in the Classroom'', borrowed something of the myth by advancing the idea that teachers' expectations of their students affect the students' performance, a view that has been called into question as a result of later research findings. Rosenthal and Jacobson held that high expectations lead to better performance and low expectations lead to worse, both effects leading to self-fulfilling prophecy. According to the Pygmalion effect, the targets of the expectations internalize their positive labels, and those with positive labels succeed accordingly; a similar process works in the opposite direct ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Unobtrusive Research
Unobtrusive research (or unobtrusive measures) is a method of data collection used primarily in the social sciences. The term "unobtrusive measures" was first coined by Webb, Campbell, Schwartz, & Sechrest in a 1966 book titled ''Unobtrusive Measures: nonreactive research in the social sciences''. The authors described methodologies which do not involve direct elicitation of data from the research subjects. Unobtrusive measures are contrasted with interviews and questionnaires, in that they try to find indirect ways to obtain the necessary data. The unobtrusive approach often seeks unusual data sources, such as garbage, graffiti and obituaries, as well as more conventional ones such as published statistics. Unobtrusive measures should not be perceived as an alternative to more reactive methods such as interviews, surveys and experiments, but rather as an additional tool in the tool chest of the social researcher. Unobtrusive measures can assist in tackling known biases such as sele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bradley Effect
The Bradley effect (less commonly the Wilder effect) is a theory concerning observed discrepancies between voter opinion polls and election outcomes in some United States government elections where a white candidate and a non-white candidate run against each other.Reddy, Patrick. (January 20, 2002).Does McCall Have A Chance?, ''Buffalo News'', p. H1 The theory proposes that some white voters who intend to vote for the white candidate would nonetheless tell pollsters that they are undecided or likely to vote for the non-white candidate. It was named after Los Angeles mayor Tom Bradley, an African-American who lost the 1982 California gubernatorial election to California attorney general George Deukmejian, a white person, despite Bradley being ahead in voter polls going into the elections. The Bradley effect posits that the inaccurate polls were skewed by the phenomenon of social desirability bias. Specifically, some voters give inaccurate polling responses for fear that, by stat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Demand Characteristics
In social research, particularly in psychology, the term demand characteristic refers to an experimental artifact where participants form an interpretation of the experiment's purpose and subconsciously change their behavior to fit that interpretation. Typically, demand characteristics are considered an extraneous variable, exerting an effect on behavior other than that intended by the experimenter. Pioneering research was conducted on demand characteristics by Martin Orne. A possible cause for demand characteristics is participants' expectations that they will somehow be evaluated, leading them to figure out a way to 'beat' the experiment to attain good scores in the alleged evaluation. Rather than giving an honest answer, participants may change some or all of their answers to match the experimenter's requirements, that demand characteristics can change participant’s behaviour to appear more socially or morally responsible. Demand characteristics cannot be eliminated from expe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Observer-expectancy Effect
The observer-expectancy effect (also called the experimenter-expectancy effect, expectancy bias, observer effect, or experimenter effect) is a form of reactivity in which a researcher's cognitive bias causes them to subconsciously influence the participants of an experiment. Confirmation bias can lead to the experimenter interpreting results incorrectly because of the tendency to look for information that conforms to their hypothesis, and overlook information that argues against it. It is a significant threat to a study's internal validity, and is therefore typically controlled using a double-blind experimental design. It may include conscious or unconscious influences on subject behavior including creation of demand characteristics that influence subjects, and altered or selective recording of experimental results themselves. Overview The experimenter may introduce cognitive bias into a study in several ways. In what is called the observer-expectancy effect, the experim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Watching-Eye Effect
The watching-eye effect says that people behave more altruistically and exhibit less antisocial behavior in the presence of images that depict eyes, because these images insinuate that they are being watched. Eyes are strong signals of perception for humans. They signify that our actions are being seen and paid attention to even through mere depictions of eyes. It has been demonstrated that these effects are so pronounced that even depictions of eyes are enough to trigger them. This means that people need not actually be watched, but that a simple photograph of eyes is enough to elicit feelings that individuals are being watched which can impact their behavior to be more pro-social and less antisocial. Empirical psychological research has continually shown that the visible presence of images depicting eyes nudges people towards slightly, but measurably more honest and more pro-social behavior. The concept is part of the psychology of surveillance and has implications for the areas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
