Quasi Experimental Research

Quasi-experimental Research - Studies in which the researchers introduce the independent variable with the intent of observing the outcome, but unlike true experimental research, group selection is not randomized.
  • In this study by Ghanbari et al., the independent variable was introduced by the the researchers to all individuals in the group, without randomization or a control group. Everyone was tested before treatment, received the same treatment, and was tested again after treatment.
  1. Ghanbari A. and Kamalgharibi S. (2013). Effect of knee joint mobilization on quadriceps muscle strength. International Journal of Health and Rehabilitation Sciences. 2(4): 186-191

Related Terms

  • Experimental research
  • Control group
  • Independent variable
  • Dependent variable
  • Bias
  • Validity


  • quasi-experimental design
  • quasi-experimental study