Conrol Psych 202

Control

Ways to rule out threat validity

Within-Subject Design

all subjects receive all levels of IV presented at different times; EACH subject experiences EVERY condition

Between-Subject Design

when different subjects in different groups experience a single condition; randomly assigned to either group

Reduce Variability

allows a researcher to restrain or guide sources of variability; hold extraneous variables constant

Control in the Lab

extraneous variables can be controlled but environment can be contrived

Subjects as their own control

individuals vary on a many dimensions; IQ, sexual history, etc.

Random assignment

each participant has an equal and independent chance of being assigned to every condition

Nuisance variables

condition in an experiment that can not easily be removed and so is made an independent variable as a means of control

Statistical control

mathematical means of comparing subjects on paper when they can not be equated as they exist in fact

Replication

repeating of an experiment to see if the results will be the same

Direct replication

repeating IDENTICAL experiments in an attempt to obtain the same results

Systematic replication

slightly DIFFERENT experiment is conducted but it tests the same hypothesis

Matching

control procedure to ensure that experimental and control groups are equated on one or more variables before the experiment

Control Group

subjects in a between subjects experiment who DONT receive treatment

Experimental Group

subjects in an experiment who receive treatment

Control Condition

a condition in a within-subjects design experiment that does not contain the experimental manipulation