Quasi experimental

Question 1

what are the features of quasi experimental study designs?

Answer 1

they contain an intervention and comparison group but do not have randomisation BUT comparison group does not equate to control, it could be baseline measurements too.

Question 2

Name 5 common quasi experimental study designs

Answer 2

Design without a control group:
1) One-Group Posttest-Only Design
2)One-Group Pretest–Posttest Design

Nonequivalent control group design:
3)Pretest-posttest comparison group design
4)Posttest only comparison group design

Interrupted time series design:
5) Interrupted time series design

Question 3

how do i improve the pretest posttest comparison group design?

Answer 3

add a pre pretest

Question 4

what is a interrupted time series design?

Answer 4

It Provides an estimate of the causal effect of a discrete
intervention

Begin from a long series of repeated measurements on a
outcome

Intervention breaks the TIME SERIES into pre- and post-
intervention segments (Usually used for a policy change/
intervention)

Interrupted Time Series (ITS) is a quasi-experimental research design used to evaluate the impact of an intervention or event over time. This method tracks data at multiple time points before and after an intervention (the “interruption”) to determine whether the intervention has caused a significant change in the outcome of interest.

Question 5

what is interrupted time series design usually used for?

Answer 5

policy change, intervention, public health matter.