Single Case Design Research
CEC-DR Issues Position Statement: Negative Effects of Minimum Requirements for Data Points in Multiple Baseline Designs and Multiple Probe Designs in the What Works Clearinghouse Standards Handbook, Version 4.0 (October, 2019)
The Division for Research occasionally publishes technical papers on our website to highlight potential issues of interest to our members. These papers generally focus on research methodology, dissemination practices, and policy and encourage discussion within our field.
Harris, Stevenson, and Kauffman’s technical paper, CEC-Division for Research Position Statement: Negative Effects of Minimum Requirements for Data Points in Multiple Baseline Designs and Multiple Probe Designs in the What Works Clearinghouse Standards Handbook, Version 4.0, highlights an important issue when utilizing single-case designs. Current What Works Clearinghouse Standards indicate that a minimum of 5 (or more) data points should be collected in each of 6 (or more) phases in order to meet WWC standards without reservations within a multiple-baseline design. The purpose of including 5 data points in each phase is to account for trend and/or variability in the data for a given phase, thus making visual analysis presumably more reliable. Harris and colleagues describe situations when a minimum of 5 data points may have a negative impact on participants and studies. As one example, an investigator may be interested in examining the impact of an instructional strategy on math fact acquisition. Repeated demonstration of a zero-baseline score may not be necessary, given a stable baseline at zero with fewer points. In fact, the authors argue on several grounds (i.e., ethical, potential impact on internal validity) that, on occasion, fewer data points in phases may suffice. The authors propose that WWC provide a description of conditions when fewer than 5 data points in a phase would be appropriate without negatively impacting the integrity of a given study.
Single Case Design: Position Statement on Negative Effects of WWC Minimum Requirements for Data Points in Multiple Baseline Designs and Multiple Probe Designs
CEC-DR Issues Guidance for Use of Single-Case Research (Feb 2018)
Over the past year, the CEC-DR Single Case Design workgroup has worked on the development of two documents intended to provide guidance to schools and districts in using single-case research to identify promising practices for children with significant behavioral and learning needs. These documents (a policy statement and a how-to guide) were recently completed and are designed to help educators distinguish reliable evidence from the jumble of fads and pseudo-scientific practices that claim to be “research-based.” Although similar guidance documents exist, Single Case Design is often overlooked as a valid approach to generating evidence-based practices for school used. These documents are intended to fill a gap in guidance provided to districts and schools, and will be shared with other CEC divisions, school administrators' organizations, and other relevant groups. Please feel free to share them with educators and policy-makers in your networks.
Many thanks to subcommittee chairs Jennifer Ledford and Wendy Rodgers, along with Tim Lewis, Sam Odom, Rob O’Neill, Ilene Schwartz, Kimberly Vannest, and Katie Zimmerman for their thoughtful work on these materials. We envision other dissemination opportunities (e.g., conference presentations, webinars) to follow their release.
Single Case Design: Policy Statement