A review of the non-equivalent control group post-test-only design
evidence and practice    

A review of the non-equivalent control group post-test-only design

Preetha Krishnan Nurse practitioner, Winnipeg Regional Health Authority, Winnipeg MB, Canada, and graduate student, College of Nursing, University of Manitoba, Winnipeg MB, Canada.

Background Quantitative research designs are broadly classified as either experimental or quasi-experimental. The main distinguishing feature of the quasi-experiment is the manipulation of the independent variable without randomisation. When randomisation or use of a control group is unfeasible, a researcher can choose from a range of quasi-experimental designs.

Aim To present the features of the quasi-experimental ‘non-equivalent control group post-test-only’ design, which aims to demonstrate causality between an intervention and an outcome.

Discussion This paper provides an overview of the non-equivalent control group post-test-only design in terms of its design features, applications and statistical analysis, as well as its advantages and disadvantages.

Conclusion The non-equivalent control group post-test-only design can be used in natural settings, where randomisation cannot be conducted for ethical or practical reasons. Although the design is less complex than some other designs, with low error propagation, it is vulnerable to threats to internal validity.

Nurse Researcher. doi: 10.7748/nr.2018.e1582


Krishnan P (2018) A review of the non-equivalent control group post-test-only design. Nurse Researcher. doi: 10.7748/nr.2018.e1582

Peer review

This article has been subject to external double-blind peer review and has been checked for plagiarism using automated software



Conflict of interest

None declared

Published online: 18 September 2018

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