Sharpley's reviews found the PRS core unsupported; Einspruch and Forman's methodological critique argued the early tests were flawed, and subsequent work still failed to rescue the hypotheses. Witkowski's thirty-year synthesis (2010) concluded the ten central NLP assumptions lacked empirical support. These reviews are why honest institutes stopped claiming science — and why our evidence pages exist.
Systematic Reviews of NLP
The field's formal evidence assessments — Sharpley's 1980s reviews, Witkowski's 2010 decade-synthesis — converge on a blunt conclusion.
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ShriViral Manek, Institute of NLP India · reviewed 30 Sept 2026