Exam 2 Flashcards
(106 cards)
experimental research design
- used for the purpose of examining causality
- researchers actively manipulate the independent variable to determine its effect on the dependent variable
- involve randomization and control groups
nonexperimental research design
-used for the purpose of describing a phenomenon in detail, explaining relationships and differences among variables, and predicting relationships and differences among variables
causality
relationship between a cause and its effect
probability
likelihood or chance that an event will occur in a situation
control
ability to manipulate, regulate, or statistically adjust for the multitude of factors that can influence the dependent variable
extraneous variables
factors that interfere with the relationship between the independent and dependent variables; confounding variable; Z variable
bias
extraneous variables influence the relationship btwn the independent and dependent variables
randomization
the selection, assignment, or arrangement of elements by chance
random sampling
technique for selecting elements whereby each has the same chance of being selected
random assignment
assignment technique in which subjects have an equal chance of being in either the treatment or the control group
between-groups design
study design where two groups of subjects can be compared
within-groups design
comparisons are made about the same subjects at two or more points in time or on two or more measures
study validity
ability to accept results as logical, reasonable, and justifiable based on the evidence presented
internal validity
degree to which one can conclude that the independent variable produced changes in the dependent variable
selection bias
- threat to internal validity that occurs when the change in the DV is a result of differences in the characteristics of subjects before they entered a study rather than a result of the IV
- can be minimized somewhat by the use of random assignment to groups
threats
forces that can change the result of a study
history
- threat to internal validity
- occurs when the DV may have been influenced by some event other than the IV that occurred during the course of the study
maturation
- threat to internal validity
- when subects change by growing or maturing
testing
- threat to internal validity
- when a pretest influences the way subjects respond to a post test
instrumentation
- threat to internal validity
- when there are inconsistencies in data collection
mortality
- threat to internal validity
- when there is a loss of subjects before the study is completed; attrition rate
attrition rate
dropout rate; loss of subjects before the study is completed
statistical conclusion validity
the degree that the results of the statistical analysis reflect the true relationship among the independent and dependent variables
type II error
when researchers inaccurately conclude that there is no relationship among the independent and dependent variables when an actual relationship does exist; when the researcher accepts the null when it should have been rejected