chapter 9: quasi-experimental & single-case experimental designs

Question 1

one-group posttest-only

Answer 1

One group, measurement after treatment

Limitation = no control/comparison, threats to internal validity (history and maturation)

Question 2

one-group pretest-posttest

Answer 2

One group, compare scores measured before and after treatment

Advantage = group comparison

Limitation = no control, threats to internal validity

Question 3

nonequivalent control group

Answer 3

similar preexisting characteristics to treatment group

Participants not randomly assigned

Compared to treatment group

Susceptible to selection differences

Question 4

nonequivalent control group posttest only

Answer 4

Limitation = no random assignment → susceptible to selection differences (preexisting differences between groups causes a difference in score rather than the treatment)

Question 5

nonequivalent pretest-posttest

Answer 5

Advantage = comparison group and scored compared before and after treatment

Limitation = no random assignment → susceptible to selection differences (preexisting differences between groups causes a difference in score rather than the treatment)

Question 6

basic time series design

Answer 6

Series of observations made in one group before and after a treatment

Advantage = identify patterns in DV

Limitation = no comparison group

Question 7

interrupted time series design

Answer 7

Series of measurements made in one group before and after naturally occurring treatment or event (beyond control of the researcher)

Advantage = identify patterns of change in DV

limitation = no comparison

Question 8

control time series design

Answer 8

Basic or interrupted time series with a nonequivalent control group

Advantage = comparisons between groups

limitation = no random assignment → cannot demonstrate cause, threat of selection differences