Internal, external, construct and statistical conclusion validities

Question 1

Validity (general idea)

Answer 1

• can i trust the results of the study?
• extent to which an effect demonstrated in research is genuine (not affected / produced by other variables)

Question 2

Four types of validity
- inte_nal
- ex_ernal
- constr_ct
- s_atistical conc_usion

Answer 2

Internal (causality): is the observed change in a DV caused by a corresponding change in hypothesized IV and not by extraneous variables
=> the study’s desin

External: the generalizability => can we apply results from sample to population (population validity) or to other ppl, contexts, time (ecological validity)

Construct: how well a given measurement scale measures the theoretical construct

Statistical conclusion: extent to which conclusions derived using a statistical procedure is valid

Question 3

What are plausible threats to internal validity?
PMSS

Answer 3

Participants’ growth and maturation (history, maturation)

Measurement process (instrumentation)

Sampling design (selection)

Statistical analyses (estimation bias)

Question 4

What occurs with single method and single informant bias?

Answer 4

1) single method => threats to construct validity

2) may bring in shared method / informant VARIANCE which is a threat to internal validity

Question 5

What is the trade off bet. Int. validity and Ext. validity?
Which one are psychologists most interested in?

Answer 5

• IV increased in lab experiment but decreases in EV
• prefer establishing an association, so IV