manipulated variable Flashcards
Impacts the dependent variable, created in order to observe the effects on dependent variable, remember IN dependent meaning it impacts the dependent variable.
Independent variable
Outcome or response of a variable
dependent variable
factor in an experiment that a scientist purposefully keeps the same
control group
the participants in an experiment whose levels on the independent variable that involves a medication therapy or intervention
treatment groups
a group in an experiment whose level on the independent variable differs from those of the treatment group
comparison group
a group in an experiment whose level on the independent variable differs from those of the treatment group in some intended and meaningful way
control group
a control group of participants who believe they are receiving treatment but who are only receiving a placebo
placebo group
another variable varies systematically along with the independent variable other, explains other explanations for the outcome
confound
two separate groups of participants experience two different conditions of the experiment, had more people
independent groups design
the really bad experiment, lacks a comparison group which makes it vunerable to the threats to internal validity
one group/pretest-posttest
what are the first three threats to consider for internal validity
design confounds, selection effects, and order effects.
a threat to the internal validity in an experiment in which a second variable happens to vary systematically along with the independent variable and therefore is an alternative explanations for the results
design confounds
a threat to internal validity that occur in an independent groups design when the kinds of participants at one level of the independent variable are systematically different from those at the other level
selection effects
in a within groups design, a threat to internal validity in which exposure to one condition changes participants responses to a later condition
order effect
more people, two separate groups of participants experience two different conditions of the experiment
Independent group
participants are randomly assigned to independent variable groups and are tested on the dependent variable once
post-test only design
participants are tested on the dependent variable once before and once after exposure to the treatment.
pretest-posttest design
participants are measured on a dependent variables at roughly the same time and a single attitudinal or behavior preference is the dependent variable.
concurrent measures design
participants are measured on a dependent variable more than once after exposure to each level of the independent variable
repeated measure design
a test to determine whether the manipulation of the independent variable actually has the intended effect
manipulation check
a threat to internal validity that occurs when an observed change in an experimental group could have emerged more or less spontaneously over time: solution include comparison group
maturation threat
external events that occur during the study that could affect the dependent variable. Solution: use a control group or match participants to control for external events
history threat
extreme scores that regress toward the mean over time. Solution: use a control group or measure the dependent variable multiple times.
regression threat/regression to the mean
participants dropping out of the study, solution: use incentives or follow up procedures to reduce attrition.
attrition threat
the pretest may affect the posttest scores, solution: use a control Group or alternate forms of the test
testing threat
changes in the way the dependent variable is measured over time, solution: use consistent measurement tools and procedures
instrumentation threat