Wallace, M. D., & Iwata, B. A. (1999).
Effects of session duration on functional analysis outcomes.
Journal of Applied Behavior Analysis,
32, 175-183.
We examined the extent to which variations in session duration
affected the outcomes of functional analyses. Forty-six
individuals, all diagnosed with mental retardation and referred
for assessment and treatment of self-injurious or aggressive
behavior, participated in functional analyses, consisting of
repeated exposure to multiple test conditions during 15-min
sessions. For each set of assessment data, new data sets based on
session durations of 10 and 5 min were prepared by deleting data
from the last 5 and 10 min, respectively, of each session. Each
graph (N = 138) was then reviewed individually by graduate
students who had previous experience conducting and interpreting
functional analyses, but who were blind to both participant
identity and session duration. Interpretations of behavioral
function based on the 10- and 5-min data sets were then compared
with those based on the 15-min data sets. All of the 10-min data
sets yielded interpretations identical to those based on 15-min
data sets. Interpretations based on the 5-min and 15-min data
sets yielded three discrepancies, all of which were the result of
increased response rates toward the latter parts of sessions.
These results suggest that the efficiency of assessment might be
improved with little or no loss in clarity by simply reducing the
duration of assessment sessions.
DESCRIPTORS: assessment, functional analysis, observation
procedures