Westworld, Michael Crichton’s 1973 film, made him wary of the dinosaur-park idea.
Westworld depicts a futuristic resort where lifelike robots entertain visitors in themed environments, including a Wild West setting. When the machines malfunction, the park’s promise of controlled entertainment collapses into a deadly threat. That premise gave Crichton an important warning about repeating the same basic concept with dinosaurs.
Crichton initially avoided writing Jurassic Park because he felt a dinosaur attraction could be too similar to Westworld. He eventually accepted the idea after developing a distinct focus: genetic engineering, scientific hubris, corporate secrecy, and chaos theory. He also chose to write the story as a novel rather than a screenplay because he doubted such an expensive dinosaur production would be made successfully as a film.
The connection explains why Westworld is the canonical answer, not Coma, Looker, or Runaway. Those films are associated with Crichton’s career, but they did not prompt this specific concern about a technologically controlled park.