## EDUC 536 Week 2: Conceptualization, Operationalization, and Measurement Reliability Validity

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•Confounding Variables:
–They can
potentially explain the relationship
between the DV and the IV. Not measured.

•Control: Essentially,
a control variable is what is kept the same throughout the experiment, and it
is not of primary concern in the experimental outcome.[3][2] Any change in a control variable
in an experiment would invalidate the correlation of dependent variables (DV)
to the independent variable (IV), thus skewing the results.[3

Control Variables (covariates):
–Variables that can
affect the outcome, but are not the focus of the study Increase precision.
from EDUC 532

•Mediating: Mediator
variables -
"In general, a given variable may be said to function as a mediator to the
extent that it accounts for the relation between the predictor and the
criterion. Mediators explain how external physical events take on internal
psychological significance. Whereas moderator variables specify when certain
effects will hold, mediators speak to how or why such effects occur." p. 1176

•Moderating: Moderator variables - "In general terms, a
moderator is a qualitative (e.g., sex, race, class) or quantitative (e.g.,
level of reward) variable that affects the direction and/or strength of the
relation between an independent or predictor variable and a dependent or criterion
variable. Specifically within a correlational analysis framework, a moderator
is a third variable that affects the zero-order correlation between two other
variables. ... In the more familiar analysis of variance (ANOVA) terms, a basic
moderator effect can be represented as an interaction between a focal
independent variable and a factor that specifies the appropriate conditions for
its operation." p.
1174

(Think about Motivation for the

Study and Prior Literature) Babbie – Ch. 5 (posted on Blackboard) EDUC 536 Salkind – Ch. 6 Review Kurpius & Stafford – Ch. 1, 9-

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