Reasoning model
Also: reasoning models, thinking model
A model trained to spend extra work on some answers. It may help with hard tasks. It can still be wrong, and speed and cost vary.
The fuller definition
A reasoning model is designed or trained to devote computation to solving multi-step tasks before or while producing an answer. Vendors implement and expose this differently.
Invented probabilities. Always picking the top candidate gives the same wording every run; sampling sometimes picks a lower one. Neither setting checks whether the sentence is true.
A concrete example
A model works through a constraint-heavy scheduling problem before returning a proposed schedule.
The distinction that matters
A longer reasoning process is not proof of correctness. Inspect the result, assumptions, and supporting work.
Related terms
Inference
The act of running a trained model to get an answer. In law the word means something else: a conclusion drawn from evidence.
Reliability & securityEvaluation (eval)
Testing an AI tool on a set of tasks to see how well it actually does.
Training & generationChain of thought
Having the model write out its steps before the final answer. It often helps, but the written steps are not proof the answer is right.
Where it is taught
What actually happens when you ask AI a question?Source and further reading
Google · Machine Learning GlossaryThe definition and example are written for this library. The link gives background, official documentation or legal authority as labelled. Legal scope depends on the jurisdiction and current text; product features depend on release and settings.