Article discusses research on orientation and mobility (O&M) for individuals with visual impairments, examining constant, variable, and absolute error (descriptive statistics that quantify fundamentally different characteristics of distributions of spatially directed behavior). It illustrates the statistics with examples, noting their…

This article reviews the development of measures that assess mobility and discusses the use of such measures in the study of factors influencing travel in natural travel environments. It traces the development of measures related to spatial orientation, provides a review of orientation research, and suggests areas for future research. (SM)