ch 7 Flashcards
Threat to Internal Validity
interfere with the ability to determine the influence of IV on DV
Threat to External Validity
interfere with the ability to determine the applicability of findings to real-world people and places
confound
a variable that a)varies systematically with the IV and b) could exert an effect on the DV
should be held constant but it varies
artifact
a variable that a) is held constant in a study and b) might represent a restricted context under which the effect will be observed
should have systematically varied but it was held at one constant
threats to internal validity ex
pseudo experiment
histroy
maturation
testing effects
confounds
threats to external validity ex
pseudo experiment
selection bias
nonresponse bias
mere measurement effect
artifact
pseudo-experiment
research design where someone tests a claim about one variable by exposing people to the variable of interest and noting that these people feel, think or behave as we expected
selection bias
sampling people from an unrepresentative sample by using imperfect sampling techniques
nonresponse bias
- the respondents are the source of the bias
- because people who chose to answer surveys are systematically different from people who choose not to do so, surveys that have low response rates may yield information that is highly misleading
history
change that occurs more or less across the board in a very large group of people such as nation or culture
maturation
specific developmental or experiential changes that occur in a particular person in a particular age cohort over time
regression toward the mean
the tendency for people who receive high or low scores on a particular measure to score closer to the mean on subsequent testing
the kinds of studies that are most likely to be influenced by regression towards the mean are ?
pretest-posttest studies that do not involve a control group
mere measurement effect
the tendency for participants to change their behavior simply because they have been asked how they would respond
testing effects
a problem is pretest-posttest designs that have no control group
refers to the tendency for most participants to perform better on a test or personality measure the second time they take it
experimental mortality or attrition
the failure of some of the participants in an experiment to complete the study
attrition rate
the proportion of people who dropped out of the study
homogenous attrition
where there is an equal level of attrition across all of the experimental conditions suffer
heterogeneous attrition
occurs when the attrition rates in two or more conditions of an experiment are noticeably different
participant reaction bias
the bias that occurs when people realize they are being studied and behave in ways that they normally wouldn’t
3 basic varieties of participant reaction bias
meet expectations
disconfirm expectations
look good
participant expectancies
occur when participants consciously or unconsciously try to behave in ways they believe to be consistent with the experimenters’ hypothesis
demand characteristics
characteristics of an experiment itself that subtly suggests how people are expected to behave
participant reactance
the tendency of participants to try to disconfirm and experimenter’s hypothesis
evaluation apprehension
refers to peoples concern about being judged favorably or unfavorably by other person
how to reduce or eliminate most forms of participant reaction bias
- increase anonymity
- give participants in the experimental and control group exactly the same expectancy
- keeping participants in the dark
experimenter bias
A threat to validity and can happen when experimenters’ expectations about their studies bias their experimental observations
two distinct forms of experimenter bias
-when researchers make biased observations in an experiment
- when experimenters treat their participants differently according to their expectations about how their participants should perform
