Web application: filters to display books, including genres and excluding genres.

Script:

  • A website has a list of ~ 10,000 books
  • A user would like to discover a book that could be enjoyed through the genre (there are 15 to choose from)
  • Mark a check box to show only books that include the genre "thriller"
  • Too many books appear that also contain the genre "horror" (the user does not like horror)
  • The user wants a way to exclude "horror" from the list returned from trillers.

I am looking for a non-clumsy way to allow the user to exclude genres that, preferably, do not disrupt or interfere with the "inclusion" list (it is a solid and simple UX that should be considered as the primary filtering method). I would also like to avoid having to list the 15 genera again on another checklist. There are other types of common filters as part of the same user interface (length, classification, search by keyword), but I just need help with the previous ones.

My only thought was maybe to keep the exclusions initially hidden unless activated in some way.

The area in the user interface is a full height side bar of ~ 250 pixels wide and can be moved independently.