7 Internal validity and experimental studies

So far, you have learnt to ask a RQ, identify different ways of obtaining data, and design the study.

In this chapter, you will learn how to ensure that the conclusions we can make are logical and sound in experimental studies. You will learn to:

  • maximise internal validity in experimental studies.
  • manage confounding in experimental studies.
  • explain, identify and manage the carry-over effect in experimental studies.
  • explain, identify and manage the Hawthorne effect in experimental studies.
  • explain, identify and manage the observer effect in experimental studies.
  • explain, identify and manage the placebo effect in experimental studies.
  • explain different descriptions of blinding.