Unit 3 Flashcards
An indication of accuracy in terms of the extent to which a research conclusion corresponds with reality. The researchers conclusion is true or correct, it corresponds to the actual state of the world
Validity
Error that occurs when the effects of two variables in an experiment cannot be separated, resulting in a confused interpretation of the results
Confounding
The difference between subjects that cannot be controlled but can only be selected
Subject variable.
The problem of confounding is particularly acute in research in which the experimenter cannot control the independent variable, when participants are selected according to the presence or absence of a condition and not selected simply to have a condition assigned to them
The extent to which the results support the theory behind the research. Can you generalize from the specific operations of your experiment to the general theoretical construct about the population in question?
Construct validity
Describe the several ways to determine if a test has construct validity
Use a manipulation check, an aspect of an experiment designed to make certain that variables have changed in the way that was intended.
You must rule out other possible theoretical explanations of the results, you may have to perform another study to rule out a threat to validity. In the case of construct validity, you must design a new study that will permit a choice between the two competing theoretical explanations of the results
How well the findings of an experiment generalized to other situations or populations
External validity
Extent to which data are shown to be the result of cause-and-effect relationships rather than accident
Statistical conclusion validity
To establish statistical conclusion validity, appropriate sampling in measurement techniques must be used, and inferential statistics must be used properly, in keeping with their underlying assumptions
Briefly describe the major threats to internal validity
Ambiguous temporal precedence, events outside the laboratory, maturation, effects of testing, regression effect, selection, mortality
A threat to internal validity. Although two variables are related, it is not clear which one is the cause and which one is the effect
Ambiguous temporal precedence
A threat to internal validity. Events that occur outside of the experiment that could influence the results of the experiment.
History. For example, different experimental conditions are presented to subjects at different times.
A threat to internal validity. A source of error in an experiment related to the amount of time between measurements
Maturation
A threat to internal validity where performance on a second test is influenced by simply having taken a first test
Effect of repeat testing
A threat to internal validity. The tendency of subjects with extreme scores on a first measure to score closer to the mean on a second testing
Regression effect
A threat to internal validity. That part of the value of a variable that can be attributed to chance
Random error
A threat to internal validity. A confound that can occur due to assignment of subjects to groups
Selection
A threat to internal validity. Dropping out of some subjects before an experiment is completed, causing a threat to validity
Mortality
Briefly describe to threats to construct validity
A loose connection between theory and method. poor measure of the theoretical constructs and suffers from poor operational definitions of theoretical constructs
An ambiguous effect of independent variables. When results are compromised because the participants perceive the situation differently than the experimenter does. Because some participants may see the situation in the same way as experimenter, but others understand it differently, experimental circumstances are ambiguous and the independent variable may be affected differently in the participants
Briefly describe three threats to external validity
Other subjects. A common indictment of psychological research is that it uses mainly college students and white rats experimental subjects due to their accessibility and presumed representativeness. The problem is that millions of species of animals exist, most of them insects. We cannot assume that any animal can be substituted for any other in all situations. Human participant should be chosen with equal attention to the representativeness relative to some larger population.
Other times. The same experiment conducted at another time may not produce the same results due to the culture and attitudes at the time.
Other settings. How will the phenomenon observed in one laboratory be related to a similar phenomenon observed in another laboratory or in the real world? Though laboratory research ensures a higher level of control, it is sometimes not easy to decide if a certain effect is simply a laboratory effect or whether it would survive transplantation to the world outside
What are the two broad categories of bias resulting from the interaction between subject and experimenter?
Role demands and experimenter bias
Participants’ expectations of what an experiment requires them to do
Role demands
