Design And Statistics

Front 1

What does the validity of a test refer to?

Back 1

Validity of a test refers to the extent to which the test measures what it was designed to measure.

Front 2

What is internal validity?

Back 2

Internal validity is extent to which the intervention or manipulation (manipulation of IV) accounts for changes in DV

Front 3

What are the most common risks to internal validity?

Back 3

1. History (event that occurs in the experiment or outside of the experiment-other than manipulation of IV- that could account for change in DV)
2. Maturation (development/decay of biological or psychological factors)
3. Testing effect (taking test more than once...e.g., pretest effect)
4. Instrumentation (change in instrument/measuring procdures during course of experiment)
5. Regression to the mean (tendency of extreme scores to regress to mean)
6. Selection bias (systematic differences in groups based on selection of subjects into groups)
7. Attrition/Mortality (differential drop-outs btwn experimental/control group)
8. Experimentor bias (reaction of experimentor may differ between groups, experimentor's procedures in study may vary over time).

Front 4

What is the Rosenthal effect/Pygmalion effect?

Back 4

The tendency for participants' performance to be effected by the expectations of the tester (students perform better than other students because the teacher expects them to)

Front 5

How do researchers safeguard internal validity?

Back 5

1. Random assignment
2. Matching subjects on possibly relevant characteristics (less powerful than random assignment, but necessary when groups cannot be randomly assigned)
3. Blocking (study the effects of extraneous subject characteristics...treat them as IV)
4. ANCOVA (analysis of co-variance...statistical procedure developed to "account for" group differences in extraneous characteristics)

Front 6

What is external validity?

Back 6

Refers to the generalizability of study/test results. It refers to the limits or boundaries of the findings.

Front 7

What are threats to external validity?

Back 7

1. Interactions between subject selection and treatment (treatment effects do not generalize to other members of the population)
2. Testing and treatment effects (treatment effects do not generalize to individuals who did not participate in the pre-testing...e.g., from demand characteristics)
3. History and treatment effects (treatment effects depend on history of testing period)
4. Demand characteristics (cues in research the alert subjects to how they should respond)
5. Hawthorne effect (tendency of subjects to respond differently when they are observed in research setting)
6. Order effects (risk in repeated-measure studies)

Front 8

What is the Hawthorne Effect?

Back 8

Tendency of subjects to behave differently when they are in a research study

Front 9

How do resarchers safeguard external validity?

Back 9

1. Random selection from population of interest
2. Conduct naturalistic/field research
3. Use single or double-blind research designs
4. Counterbalancing (e.g., vary the order of treatment strategies among participants to eliminate order effects)
5. Stratified random sampling (select random sample from each of several subgroups of target population)
6. Cluster sampling (the unit of sampling is naturally occurring groups of individuals rather than sampling on an individual level)

Front 10

What is Content Validity?

Back 10

The degree to which items on a test represent the domain that the test is supposed to measure (e.g., does a test of depression include items that measure vegetative sx, cognitive sx, mood sx, etc.)