This document contains the validation tables for the instrument designed to assess higher-order critical thinking skills (analysis, synthesis, and evaluation). It includes the ratings provided by seven expert judges for 24 open-ended items, evaluated in terms of coherence, relevance, clarity, and sufficiency. The statistical analysis is based on Aiken’s V coefficient to establish content validity, contributing to the credibility criterion within a qualitative research design. These materials supported the refinement of the instrument prior to its implementation in a didactic intervention in quantum physics education based on philosophical strategies.