Fisher, W. W., Kelley, M. E., & Lomas, J. E. (2003).
Visual aids and structured criteria for improving visual inspection and interpretation of single-case designs.
Journal of Applied Behavior Analysis,
36, 387-406.
Because behavior analysis is a data-driven process, a critical
skill for behavior analysts is accurate visual inspection and
interpretation of single-case data. Study 1 was a basic study in
which we increased the accuracy of visual inspection methods for
A-B designs through two refinements of the split-middle (SM)
method called the dual-criteria (DC) and
conservative dual-criteria (CDC) methods. The accuracy of these
visual inspection methods was compared with one another and with
two statistical methods (Allison & Gorman, 1993; Gottman,
1981) using a computer-simulated Monte Carlo study. Results
indicated that the DC and CDC methods controlled Type I error
rates much better than the SM method and had considerably higher
power (to detect real treatment effects) than the two statistical
methods. In Study 2, brief verbal and written instructions with
modeling were used to train 5 staff members to use the DC method,
and in Study 3, these training methods were incorporated into a
slide presentation and were used to rapidly (i.e., 15 min) train
a large group of individuals (N = 87). Interpretation
accuracy increased from a baseline mean of 55% to a treatment
mean of 94% in Study 2 and from a baseline mean of 71% to a
treatment mean of 95% in Study 3. Thus, Study 1 answered basic
questions about the accuracy of several methods of interpreting
A-B designs; Study 2 showed how that information could be used to
increase the accuracy of human visual inspectors; and Study 3
showed how the training procedures from Study 2 could be modified
into a format that would facilitate rapid training of large
groups of individuals to interpret single- case designs.
DESCRIPTORS: _assessment, behavior analysis, data analysis,
interrater agreement, visual inspection
This article is available in full as an Adobe Acrobat pdf
file through the JABA Articles Web Page.