Computing device and computing method

A computing device comprising:

• a processor that executes a program;
• a storage device that stores the program;
• and
• a document set communicating unit that is capable of accessing a document set including a plurality of documents collected in advance, wherein
• the storage device further stores a metadata DB specifying a corresponding relationship between each of the documents included in the document set and a keyword that is at least one word, and
• the processor is configured to perform:
• keyword extracting processing of extracting an extracted keyword that is a word, from a user prompt that is a question entered by a user;
• first narrowing-down processing of narrowing down the documents in the document set based on similarity between the user prompt and the documents;
• second narrowing-down processing of narrowing down the documents in the document set based on the extracted keyword and the metadata DB;
• and
• integrated narrowing-down processing of narrowing down the documents in the document set using the first narrowing-down processing and the second narrowing-down processing.