A data search and retrieval system that, in response to a search query, dynamically selects and applies a model of information to be returned to a user. The model may be selected based on the search query directly or indirectly based on data returned by a search engine applying the query. For this purpose, the system may include an index of models, similar to a search index. Models may be authored and contributed to the search and retrieval system by third parties, and an association between each such contributed model and characteristics of a search query, such as specific search query terms, may be stored in the index of models. A user of the search and retrieval system may provide feedback on a model that was used to generate information in response to the user's search query, and such feedback may be used to update the index of models.