The phrase 'credit-assignment' in Minsky & Papert's Perceptrons appears only in the 1988 Expanded Edition's Epilogue defending Rosenblatt — not in the 1969 original

The phrase "credit-assignment" does occur in the digitized text of Minsky & Papert's Perceptrons — but in the 1988 Expanded Edition's added end matter, where the authors defend Rosenblatt's learning rule against 1980s connectionist critics: "First, Rosenblatt's credit-assignment method turned out to be as effective as any such method could be." Two independent Internet Archive scans of the Expanded Edition index this identical sentence at scan pp. 316/318, and no occurrence of "credit assignment" appears anywhere earlier in either scan.

The location places it beyond the 1969 first edition's text. The Expanded Edition runs to 292 printed pages (Internet Archive item metadata) versus the 1969 first edition's 258 pages (1969 Science review citation line) — the ~34-page difference being the added Prologue and Epilogue; the passage sits at scan pp. 316–318, in the Epilogue region well past where the 1969 text (ending p. 258) concluded. Wikipedia independently places the same passage in the authors' retrospective rebuttal. A web-search synthesis claiming a "section 11.7 / Samuel's checkers" credit-assignment discussion inside the 1969 body could not be reproduced against the primary index and is treated as a likely conflation with Minsky's 1961 paper.

This is the same retrospective-relabel pattern the vault documents for claim-werbos-1974-no-credit-assignment-language (absent entirely) and myth-structural-credit-assignment-from-minsky-1961 (a later qualifier bolted on): a credit-assignment term reads as though native to a founding text but, on primary inspection, is a later addition. Minsky had named the (temporal) credit-assignment problem in 1961 (claim-minsky-1961-named-credit-assignment), eight years before Perceptrons. The remaining gap — a standalone 1969 first-edition scan for a direct diff — is routed to question-verify-perceptrons-1969-credit-assignment-absent.