No source located states Stuart Dreyfus's actual RAND employment start date, including his own 2002 first-person retrospective

rand-corporationstuart-dreyfusrufus-isaacsrichard-bellmanprimary-verificationunverified-mechanism

The document most likely to carry Stuart Dreyfus's own stated RAND start date is his 2002 Operations Research retrospective, "Richard Bellman on the Birth of Dynamic Programming" — a Tier 1 primary, his own authored piece in his own professional venue, about the RAND milieu he worked in. The essay recounts Bellman's RAND history from "the summer of 1949... until 1955" entirely in Bellman's own quoted words, and never states when Dreyfus himself joined RAND or began working with Bellman there. Dreyfus's Wikipedia entry, his UC Berkeley IEOR faculty page, and the Mathematics Genealogy Project each describe his RAND role — programmer on the JOHNNIAC computer, later co-author with Bellman of Applied Dynamic Programming — without dating its start. No obituary, CV, oral-history transcript, or RAND personnel record for Dreyfus was found.

[unverified — could not confirm or deny]: whether Dreyfus's RAND tenure began early enough to overlap Rufus Isaacs's 1948–1954 RAND window remains open on direct evidence. The companion finding that Dreyfus's earliest located RAND papers cluster in 1956 (claim-stuart-dreyfus-earliest-rand-papers-date-to-1956) is circumstantial and does not settle it. See question-verify-stuart-dreyfus-rand-start-date-overlap-with-isaacs.