Behavioral Dimensions

Physical Dimensions

The most common physical dimensions of behavior include shape, form, or topography; locus, and force or capacity.

Shape, form, and topography refer to the physical appearance of the behavior and the series of physical actions involved; for example, “raises hand”; “extends arm to the front of the body, palm up, with the upper arm parallel to the floor and forearm at an angle at least 160° relative to the upper arm.” Physical dimensions are most useful when the specific form of the behavior is of special importance, as in physical therapy. For example, “raises hand” as a description of behavior might be improved by adding a dimension of locus or function (e.g., “raises hand to get teacher's attention”) or by some mention of collateral behaviors that should not occur (e.g., “raises hand to get teacher's attention without speaking or making noise”). The description could be made more precise by adding references to the right or left hand and how high above the student's head the hand must be raised, but those additions might exclude variations of the behavior that are functionally equivalent. A physical dimension of a behavior should not be included as part of a definition of a behavior if that dimension would be useful in monitoring changes in behavior. The physical therapist's interest in arm extension, for example, might be better served by using the angle of extension as a measure of progress rather than as a defining characteristic of the behavior per se.

Locus refers to the part of the environment to which the behavior is directed; for example, “points to [Page 1183]correct answer” and “touches right index finger to end of nose.” Locus is most useful when the context or focus of the behavior is of special interest.

Force or capacity refers to the physical effort involved or the amount of material encompassed by the behavior; for example, “pulls starting cord with at least 10 pounds of force” or “carries at least 3 logs at a time.” These dimensions of behavior are most useful when they are critical for achieving some desired effect or outcome.

...