Pilot Studies 

Pilot Study: A small-scale version of an investigation that takes place before the real investigation is conducted. The aim is to check that procedures, materials, measuring scales, etc, work. The aim is also to allow the researcher to make changes or modifications if necessary.

Single-Blind Procedures: Any information that might create expectations is not revealed until the end of the study to control for the confounding effects of demand characteristics.

Double-Blind Procedure: Neither the participants nor the researcher who conducts the study is aware of the aims of the investigation. These are important for drug trials with the use of placebos.