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Position Papers

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


Increasing the Involvement of Culturally and Linguistically Diverse Students in Special Education Research, DR White Paper (2015)

Between 2013 and 2015, DR developed a white paper on increasing the involvement of culturally and linguistically diverse students (CLD) in special education research.  This development effort was undertaken by two of the division's committees, the Diversity Committee and the Research and Families Committee.  In addition to committee members who led this effort, other special education researchers offered perspectives and thoughtful feedback during the paper's development for which we are grateful.  The authors of this white paper are identified in the paper.

The primary purpose of this paper was twofold:  to determine the inclusion of CLD children and youth in empirical studies and to provide recommendations to the field to further increase their participation in the strength of this research base.

Readers are encouraged to consider the white paper's perspectives and to discuss how its recommendations can be applied or expanded.  DR welcomes feedback on the paper, directed to Dr. Terese Aceves, Chair of the DR Diversity Committee at


Thinking and Communicating About Evidence-based Practices in Special Education, DR White Paper (2011)

Evidence-based practice is an increasingly popular term in special education--we see evidence-based practices promoted frequently at conference and in trainings. Yet many of these practices have questionable research support. Indeed, many educators do not understand what exactly evidence-based practices mean and use the term inappropriately -- confusing it with phrases such as best practice and research-based practice. Accordingly, many special educators are wary of evidence-based reforms and remain uncommitted to using evidence-based practices. In this white paper, the CEC Division for Research clarifies what evidence-based practices are, and what they are not, so that educators can understand and communicate clearly about evidence-based practice and the important role they can play in improving outcomes for students with disabilities. 

Last Updated:  30 January, 2021

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