True experimental designs

Question 1

What is a pre-experimental design?

Answer 1

used to analyse effects of treatment so researchers know if investment is worthwhile

Question 2

Define one-shot case study design

Answer 2

• practices treatment of a single group
• only takes a single measurement after treatment

Question 3

Define one-group pretest-posttest design

Answer 3

a single case is observed at 2 time points, one before treatment and one after treatment

Question 4

Define static-group comparison

Answer 4

a group that has experienced some treatment is compared with one that has not

Question 5

What is a true experimental design?

Answer 5

statistical approach to establishing causal relationship between variables

Question 6

What is a post-test only control group design?

Answer 6

• participants are randomly assigned to either treatment group or control group
• after intervention post-test is conducted on both groups to measure effects of intervention

Question 7

What is pre-test post-test control group design?

Answer 7

• similar to post-test only design but includes a post-test before intervention
• pre-test to ensure groups are equivalent at start of study

Question 8

What is the Solomon four-group design?

Answer 8

• two control groups and two experimental groups.
• One control group and one experimental group are given a pre-test, then experimental groups receive the intervention, and finally, all groups are given a post-test.

Question 9

What are factorial designs?

Answer 9

experiments whose design consists of 2 + factors, each with discrete possible values/levels

Question 10

What is variability in the execution of X?

Answer 10

idea that the same treatment or intervention (X) can be executed in different ways in different contexts

Question 11

What is sequential refinement of X and Novel control groups?

Answer 11

process of refining the treatment (X) over time, based on the results of previous studies

Question 12

What are differences in assignment in experiments and quasi-experiments?

Answer 12

• experiment: random assignment
• quasi: non-random assignment. assigned according to their choosing/that of researcher

Question 13

What are differences in control group between experiment and quasi experiment?

Answer 13

experiment: always include a control group
quasi: may have room for confounding

Question 14

What are differences in level of evidence between experiment and quasi-experiment?

Answer 14

experiment: randomised trial is at highest level of hierarchy of evidence
quasi experiment is one level below experimental study in hierarchy of evidence

Question 15

What are advantages and limitations of experimental designs?

Answer 15

+ minimise bias and confounding
- can be high cost and ethically/practically infeasible

Question 16

What are advantages and limitations of quasi-experimental designs?

Answer 16

+ can be used in situations where experiment is not ethically/practically doable
+ can work with smaller sample sizes than randomised trials
- more susceptible to bias and confounding