Observational Measurement of Behavior

About the Authors

Paul J. Yoder, Ph.D.

Professor of Special Education, Department of Special Education, Box 220, Peabody College, Vanderbilt University, Nashville, Tennessee 37203

For more than 30 years, Dr. Yoder has used observational measurement to study communication and language development in children with disabilities and how parental interaction influences their immediate and sustained use of nonverbal and verbal communication acts. Throughout his career, Dr. Yoder has contributed to the empirical basis for decisions affecting the scientific utility of observational variables. He teaches graduate courses on observational measurement and research design at Vanderbilt University.

Blair P. Lloyd, Ph.D., BCBA-D

Assistant Professor of Special Education, Department of Special Education, Box 228, Peabody College, Vanderbilt University, Nashville, Tennessee 37203

Dr. Lloyd’s research focuses on individualized assessment and intervention for students with persistent challenging behavior. She is an active user of observational measurement and sequential analysis methods in her own research and has published multiple methodological papers on sequential analysis. She teaches graduate courses in experimental analysis of behavior and single-case research design.

Frank J. Symons, Ph.D.

Professor, Department of Educational Psychology, College of Education and Human Development, 56 East River Road, Education Sciences Building, University of Minnesota, Minneapolis, Minnesota 55455

Dr. Symons is a Distinguished McKnight University Professor in Special Education and Educational Psychology at the University of Minnesota. His research agenda positions him in the crossroads of interdisciplinary inquiry in behavioral disorders and neurodevelopmental disabilities with several specific foci, including self-injury, pain, and Rett syndrome. Many of his approaches rely on direct observational methods.

Chapter 1: Introduction to Systematic Observation and Measurement Contexts

The purpose of this chapter is to review several underlying issues involved in observational measurement of behavior. These issues, although not always articulated in a given research report, are critical to understanding the logic behind different research approaches to quantifying behavior using systematic direct observation. We define the book’s central topic: systematic observation using count coding and promote hypothesis-driven research as a general approach to maximize a study’s scientific rigor and interpretability.

Systematic Observation Using Count Coding

The systematic observation approach to measurement requires that before beginning data collection, the following elements have been decided: the procedure (i.e., type of session) to observe, the definitions of key behaviors, and the type of number used to quantify the phenomenon of interest. An example is an observer recording the presence, quality, or amount of communication from a 15-minute parent–child interaction session.

Alternatives to Systematic Observation

Alternatives include self-report, asking participants what they generally do, and third-party report, asking people who have experience with the participant to draw conclusions about behaviors. Examples of these methods are personality inventories and parental inventories of child language use.

The Rationale for Systematic Observation Using Count Coding

Systematic observation tends to be more accurate and therefore more valid than self-report and third-party reports when measuring the particular social and nonsocial contexts of behavior. It is particularly relevant when the participant is preverbal or cognitively impaired, as they cannot self-report.

Generalized Person Characteristics

When measuring a person's behavior, the underlying phenomenon may be transient and context dependent or stable and generalized. Context-dependent behaviors vary due to eliciting attributes of the measurement context, whereas generalized person characteristics are stable and long-lasting.

Table 1.1: Attributes of Systematic Observation Using Count Coding

Reliability and Validity

Reliability refers to the consistency of a measure, while validity refers to how well a measure represents what it claims to measure. The relative scientific utility of observational variables is judged by different types of reliability and validity criteria depending on where the variable is located on the continuum of context-dependent behavior to generalized person characteristic.

Table 1.3: Summary of Criteria for Evaluating Relative Scientific Value for Each Object of Measurement

Conclusion

In this chapter, we defined systematic direct observation using count coding and discussed the distinction between measuring context-dependent behaviors and two types of person characteristics. This distinction is crucial for interpreting a study and for making measurement decisions affecting the measures’ psychometric properties.