Developed by William C. Eddy, the official name was Radio Technician Selection Test (RTST, Nav Pers 16578), but this designation was rarely used.
Since 1924, the Radio Materiel School (RMS), located on the campus of the Naval Research Laboratory (NRL) in Washington, D.C., had provided advanced maintenance training for selected men with a rating of electrician's mate or radioman in the U.S. Navy and Coast Guard.
As the 1940s began and the Navy prepared for the expected war, thousands of new ships, aircraft, submarines, and shore stations were being built, all needing electronics technicians.
These would mainly come from volunteers and draftees who, unlike the RMS students from the Regular Navy, would not have experience as apprentices; therefore, a comprehensive classification examination was needed for admission.
[5][6] Therefore, the Eddy Test needed to identify students with the basic capability and psychological fitness to pursue such instruction.
[7] January 12, 1942, a prototype Primary School was opened using laboratories of Eddy's experimental television station in the "Loop" of downtown Chicago.
The prototype school quickly evolved into an extensive operation called Radio Chicago; its functions included centralized grading all of the Eddy Tests.
[13] These numbers show that only a small fraction initially passed the Eddy Test, and that, even with this, the failure rate in the overall program was some 60 percent.
In 1951, the Bureau of Naval Personnel contracted with the Advanced School of Education, Teachers College, Columbia University, to develop a new Electronic Technician Selection Test (ETST).
The contract called for this to be "somewhat less difficult than the RTST, with a maximum discrimination at or near the seventy-fifth percentage of the general high school population.