[3] Clark's husband Willis had developed the Los Angeles Diagnostic Tests in the Fundamentals of Arithmetic, which she bought the rights to sell.

[4] One year later, she heard from her first customer: the Kansas City school district.

[2] On June 30, 2015 McGraw-Hill Education announced that Data Recognition Corporation (DRC) had agreed to acquire "key assets" of the CTB/McGraw-Hill assessment business.

[10] In 2002, CTB reportedly had a 40 percent share of the test design market, ranking second of the four major companies in the industry.

[11] In 2011 CTB acquired Bookette, a privately held software company.