psyc 332 ch 10 Flashcards
Assignment bias
A threat to internal validity that occurs when the process used to assign different participants to different treatments produces groups of individuals with noticeably different characteristics
Cohort effects
Differences between age groups that are caused by characteristics or experiences other than age Also called generation effect
Cohorts
Individuals who were born at roughly the same time and grew up under similar circumstances
Crosssectional developmental research design
A developmental design comparing different groups of individuals each group representing a different age
Dependent variable
In an experiment the variable that is observed for changes to assess the effects of manipulating the independent variable In nonexperiments and quasi experiments the dependent variable is the variable that is measured to obtain the scores within each group The dependent variable is typically a behavior or a response measured in each treatment condition
Developmental research designs
Nonexperimental research designs used to examine the relationship between age and other variables
Differential effects
In a research study timerelated threats to internal validity that affect the groups differently For example differential history effects differential instrumentation effects differential maturation differential testing and differential regression
Differential research design
A nonexperimental research design that compares preexisting groups rather than randomly assigning individuals to groups Usually the groups are defined by a participant characteristic such as gender race or personality
Generation effects
Differences between age groups that are caused by characteristics or experiences other than age See cohort effects
History
A threat to internal validity from any outside event that influences the participants scores in one treatment differently than in another treatment
Instrumentation
A threat to internal validity from changes in the measurement instrument that occur during the time a research study is being conducted Also known as instrumental bias or instrumental decay
Interrupted time series design
A quasi experimental research design consisting of a series of observations before and after an event The event is not a treatment or an experience created or manipulated by the researcher
Longitudinal developmental research design
A developmental research design that examines development by making a series of observations or measurements over time Typically a group of individuals who are all the same age is measured at different points in time
Maturation
A threat to internal validity from any physiological or psychological changes that occur in a participant during the time that research study is being conducted and that can influence the participants scores
Nonequivalent control group design
A research design in which the researcher does not randomly assign individuals to groups but rather uses preexisting groups with one group serving in the treatment condition and another group serving in the control condition
Nonequivalent group design
A research study in which the different groups of participants are formed under circumstances that do not permit the researcher to control the assignment of individuals to groups and the groups of participants are therefore considered nonequivalent
Nonexperimental research strategy
A research strategy that attempts to demonstrate a relationship between two variables by comparing different groups of scores but makes little or no attempt to minimize threats to internal validity or to explain the relationship
Onegroup pretest posttest design
A nonexperimental design involving one measurement before treatment and one measurement after treatment for a single group of participants
Participant attrition
The loss of participants that occurs during the course of a research study conducted over time Attrition can be a threat to internal validity Also known as participant mortality
Participant mortality
See participant attrition
Post test only nonequivalent control group design
A nonexperimental design in which one group is observed measured after receiving a treatment and a second nonequivalent group is measured at the same time but receives no treatment
Pre post designs
Quasiexperimental and nonexperimental designs consisting of a series of observations made over time The goal is to evaluate the effect of an intervening treatment or event by comparing observations made before versus after the treatment
Pretest posttest nonequivalent control group design
A quasi experimental research design comparing two nonequivalent groups one group is measured twice once before treatment is administered and once after The other group is measured at the same two times but receives no treatment
Quasi experimental research strategy
A research strategy that attempts to limit threats to internal validity and produce cause and effect conclusions like an experiment but lacks one of the critical components either manipulation or control that is necessary for a true experiment Typically compares groups or conditions that are defined with a nonmanipulated variable
Quasi independent variable
In a quasiexperimental or nonexperimental research study the variable that differentiates the groups or conditions being compared Similar to the independent variable in an experiment
Singlecase designs
Experimental research designs that use the results from a single participant or subject to establish the existence of a causeand effect relationship See singlesubject designs
Singlesubject designs
Experimental research designs that use the results from a single participant or subject to establish the existence of a causeand effect relationship Also known as singlecase designs
Statistical regression
A statistical phenomenon in which extreme scores high or low on a first measurement tend to be less extreme on a second measurement considered a threat to internal validity because changes in participants scores could be caused by regression rather than by the treatments Also known as regression toward the mean
