"Every great scientific truth goes through three stages. First, people say it conflicts with the Bible. Next they say it had been discovered before. Lastly they say they always believed it"
- Louis Agassiz
Dr. McGrew has served as a measurement consultant to a number of psychological test publishers, including Riverside Publishing, the Psychology Corporation (now Pearson Assessments), School House Educational Services, and CTB/McGraw-Hill.
Dr. McGrew has also served as a measurement and research consultant or advisory board member for a number of national research studies and organizations including:
- U. S. Department of Education—Office of Special Education Programs (OSEP)
- National Center on Educational Outcomes (NCEO) for students with disabilities
- Stanford Research Institute (SRI)
- American Institutes for Research (AIR)
- National Accessible Reading Assessment Project (NARAP)
- National Academy of Science (NAS)
- National Academy on Education (NAE)
- National Center on Student Progress Monitoring
- National Special Education Elementary Longitudinal Study (SEELS)
- National Longitudinal Transition Study-2 (NLTS2)
- NCES Early Childhood Longitudinal Study (ECLS)
- American Association for Intellectual and Developmental Disabilities (AAIDD) Death Penalty Task Force
- Intelligence theory and testing consultant to the Dharma Bermakna Foundation and the Universatas Gadja Mada (UGM) for the development of the Indonesian AJT Cognitive Assessment Development Project (2014 to present).
- Intelligence researcher consultant at Ayrton Senna Institute (Instituto Ayrton Senna) for the development of large scale assessment methods for 21st Century Skills (Social Emotional Learning; Critical Thinking, Complex Problem Solving, Creativity)