Chapter 13
A Checklist for Judging Experiments
IN THIS CHAPTER
The added value of experiments
Criteria for a good experiment
Action items for evaluating an experiment
In this chapter, you go behind the scenes of experiments — the driving force of medical studies and other investigations in which comparisons are made. You find out the difference between experiments and observational studies and discover what experiments can do for you, how they’re supposed to be done, and how you can spot misleading results.
Experiments versus Observational Studies
Although many different types of studies exist, you can boil them all down to basically two different types: experiments and observational studies. An observational study is just what it sounds like: a study in which the researcher merely observes the subjects and records the information. No intervention takes place, no changes are introduced, and no restrictions or controls are imposed. For example, a survey is an observational study. An experiment is a study that doesn’t simply observe subjects in their natural state, but deliberately applies treatments to them in a controlled situation and records the outcomes (for example, medical ...