Due to their success, he founded the not-for-profit Measurement Research Center on the Iowa campus to score these tests, which was later acquired by Westinghouse, NCS, and its present owner, Pearson PLC.
Although it is now administered by the College Board, the competing organization to ACT, Lindquist developed the first National Merit Scholarship Qualifying Tests.
Although many of his colleagues at the University of Iowa contributed to the invention, Lindquist is generally credited with this development and is the sole inventor listed on U.S. Patent 3,050,248 (Filed 1955, granted 1962).
Lindquist's first optical mark recognition scanner used a mimeograph paper-transport mechanism directly coupled to a magnetic drum memory.
His 1940 book, "Statistical Analysis in Educational Research", laid the groundwork for the need to interpret testing data in smaller settings using accessible means.
He was the editor of the first edition of the then definitive work, Educational Measurement (1951) and contributed his own chapter outlining the problems and issues facing his field.