Retrieval is a task of retrieving documents/person/item of interest from a corpus. Clustering is finding out, what are related groups of people or items.
- If someone is listening to a song / watching movie/tv shows, she would be interested in watching similar song/movie/show.
- If someone on the e-commerce website/app, likes/purchase a product, she would be interested to see/purchase similar looking products.
- If someone is searching for an image, she would love to see the similar images.
- If an investigation officer is reading/referring to a case file w.r.t. a particular case, she would love if the intelligent retrieval system brings her another set of case files (with most closely related file on the top) that are similar/related.
- If a person is reading an article/news of interest, what an intelligent retrieval system should do is to retrieve another article/news that he might be interested in reading.
- If you are a user on some social network and based on features of you as a user. You want to be presented with other people that you might want to connect with.
- Discovering groups of patients with related medical conditions.