McGraw-Hill's Acuity Launches Adaptive Assessment Solution

Published April 28, 2015

By Communications Team

Acuity's ShadowCAT algorithm guarantees test requirements are met for all students, while providing more precise scores.

NEW YORK, April 28, 2015 /PRNewswire/ -- McGraw-Hill today launched a new computer adaptive test (CAT) for Acuity®, a K-12 interim assessment solution available in Math and English Language Arts. The new adaptive methodology, called ShadowCAT™, uses a shadow-test algorithm to ensure that all test requirements are met while maximizing the information obtained from each test taker to provide a valid, precise score for every student.

The Acuity adaptive solution is a key component of the Acuity College and Career Readiness (CCR) assessment solution, a new suite of interim assessments for Grades 3–8 that uses all assessment items written to the new college and career readiness standards. Recently recognized as a finalist for Best Student Assessment Solution by the 2015 SIIA CODiE Awards, Acuity CCR assessments are the only interim assessments that reflect the blueprint, rigor, item types, and expectations of the next-generation summative exams.

Acuity CCR is the first assessment solution in K-12 education to employ this methodology for adaptive testing. Developed by McGraw-Hill CTB Chief Research Scientist Dr. Wim van der Linden ("Linear Models for Optimal Test Design", van der Linden 2005), the assessment field recognizes the ShadowCAT methodology as the superior adaptive testing algorithm (see "A Comparison of Four Item-Selection Methods for Severely Constrained CATS," He, Diao, And Hauser, 2014).

During an adaptive testing experience in Acuity, the ShadowCAT algorithm:

  • Creates a complete and optimal test form after each response to a question.
  • Presents a student with the next, single optimal test question selected from the form (the remainder of the form is not seen by the student, hence the name shadow test).
  • Creates a new complete and optimal test as soon as the student answers the optimal question, and delivers the most ideal item from that test to the student.
  • Repeats this process until all test requirements have been fulfilled.
  • Avoids selecting test questions that lead to future violations of any test requirement, which results in more precise, valid, reliable, and comparable scores for individual students and student groups over time.

Educators benefit immediately from Acuity CCR adaptive assessments with detailed reports that uncover each student's strengths and opportunities for improvement in relation to college and career readiness standards. Adaptive assessments include a variety of assessment question types, including technology-enhanced items that are automatically scored by Acuity without requiring any manual scoring by educators.

Reports include scaled scores for tracking progress, percentile ranks, and mastery levels for each college and career readiness-reporting category. Unlike other adaptive assessment solutions, Acuity CCR adaptive reports enable educators to view items delivered to each student, with a focus on using assessment results to improve student learning.

"After years of in-depth research and development, we have created a methodology that immediately adapts to a student's specific knowledge level," said Christine Willig, president of McGraw-Hill's K-12 group. "Our Acuity College and Career Readiness adaptive assessments reduce test anxiety and increase student motivation by delivering test questions that are more aligned to each student's ability, while also providing more accurate scores that educators can count on to target instruction."

For more information about the Acuity College and Career Readiness adaptive assessment solution for Grades 3-8, visit:

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