Observing and quantifying behaviors in natural or clinical settings has long produced challenges for researchers and clinicians. Although nurses are uniquely positioned to conduct behavioral research, they may not be well acquainted with behavioral observation strategies. The author identifies several problems commonly encountered while studying behavior in natural settings and suggests methods for enhancing validity and reliability through videotaped observations. Results of a newly developed calibration procedure are discussed with implications for rater training. Nurse clinicians and researchers should find this information useful for evaluating interventions in clinics, homes, and other applied settings.