The antonyms for the word "more heuristic" includes terms such as systematic, didactic, non-exploratory, rigid, and non-experimental. While being heuristic implies that something is open to exploration, creativity, and innovation, its opposite signifies a process that is fixed, rigid, and lacks experimentation. A systematic approach, on the other hand, refers to a methodical approach that follows a set of organized procedures. A didactic method relates to a teaching style that follows a fixed curriculum, lacking the exploratory approach that a heuristic method offers. Therefore, the antonyms for "more heuristic" denotes a more rigid, fixed, and restricted approach.