Observation: a valuable data collection strategy for research with children.

This study introduces the basic concepts of observational research by defining the terms and discussing some of the critical issues specific to observational research. Observational methods signify a systematic approach to quantifying behavior. A discussion of the major concerns in observational research is presented. These concerns include defining the coding categories; identifying the unit of measurement, the method of recording the observation, and deciding on a sampling strategy; training of observers; and interrater and intrarater reliability.