Multiple Choice and Classification

You can ask Claude to classify inputs as follows.


Claude is a conversational agent, so often it will explain at length why it selected a given option. If you just want a fast multiple-choice answer and no explanation, you can put words in Claude's mouth and have Claude respond in a particular way.

For example, if the available options start with (, you can end your prompt with an Assistant message "My answer is (". That way you can immediately get a response in the first token.

RolePrompt
UserYou are a customer service agent that is classifying emails by type.

Email:
<email>
Hi -- My Mixmaster4000 is producing a strange noise when I operate it. It also smells a bit smoky and plasticky, like burning electronics. I need a replacement.
</email>

Categories are:
(A) Pre-sale question
(B) Broken or defective item
(C) Billing question
(D) Other (please explain)
AssistantMy answer is (
RoleResponse
AssistantB) Broken or defective item

Note: You can also rewrite this prompt using a system prompt. It would involve moving everything in the User role except the email into the system parameter. See system prompt prompting techniques for more details.