[8] This broad-based research program attracted many individuals who distinguished themselves in their fields, often while at ETS but also in subsequent professorial positions.

Among the more influential scientists have been Harold Gulliksen (whose book, Theory of Mental Tests, helped codify classical test theory);[9][10] Frederic Lord (item response theory); Samuel Messick[11] (modern validity theory); Robert Linn (known for testing and educational policy); Norman Frederiksen (performance assessment); Ledyard Tucker (test analysis, including inventing the "Angoff Method" of standard setting); Donald Rubin (missing data and causal modeling from observational data); Karl Jöreskog (structural equation modeling and confirmatory factor analysis); Paul Holland (differential item functioning, test equating, causal modeling); Howard Wainer (differential item functioning, Testlet Response Theory, statistical graphics); John Carroll (language testing and cognitive psychology); Michael Lewis (infant cognitive, social, and emotional development); Irving Sigel (children's cognitive development);[12] Herman Witkin (cognitive and learning styles); K. Patricia Cross (adult education); Samuel Ball (an evaluation researcher who documented the positive educational effects of Sesame Street); David Rosenhan (known for the Rosenhan experiment, which challenged the validity of psychiatric diagnosis); Jeanne Brooks-Gunn (the effects of poverty on infant, child, and adolescent development); Robert J. Mislevy (Evidence-Centered Design); and Anthony Carnevale (education and the workforce).

Among the key scientific contributions were: ETS' international headquarters is located on a 376-acre (1.52 km2) campus outside of Princeton, New Jersey in Lawrence Township, Mercer County;[26][27][28] processing, shipping, customer service and test security is in nearby Ewing.

ETS is responsible for coordination among the nine NAEP Alliance contractors, for item development, and for design, data analysis, and reporting.

ETS Global took over this role in 2008 from Edexcel, a subsidiary of Pearson, which had encountered significant and repeated problems in carrying out the marking and processing contract.

[37] The ETS contract with the QCA was terminated in August 2008, with an agreement to pay back £19.5m and cancel invoices worth £4.6m.

[43] Due to its legal status as a non-profit organization, ETS is exempt from paying federal corporate income tax on many, but not all, of its operations.

[45] Problems administering England's national tests in 2008 by ETS Europe were the subject of thousands of complaints recorded by the Times Educational Supplement.

A lack of comprehensive planning and testing by ETS of its systems and processes was a key factor in the delivery failure; In 1983, students of James A. Garfield High School in East Los Angeles, California, achieved unexpectedly high exam results on the ETS Advanced Placement Exam.

[52] Americans for Educational Testing Reform (AETR) claims that ETS is violating its non-profit status through excessive profits, executive compensation, and governing board member pay (which the IRS specifically advises against[53]).

AETR further claims that ETS is acting unethically by selling test preparation materials, directly lobbying legislators and government officials, and refusing to acknowledge test-taker rights.

Secret filming of government-approved English exams needed for a visa showed entire rooms of candidates having the tests faked for them.