Limiting Search Boundaries
Scoped search allows users to limit their search to a section or type of content on a website instead of searching everything in one go. Typically, it is implemented in two ways: drop-down scope selection and autocomplete scope suggestions , which appear below or within the search box.
Brookings.edu: Drop-down scope selectors included within the search box require users to open the menu to see the options available.
Google Shopping Express: Autocomplete scope suggestions : as the user types the search terms, categories are automatically suggested just below the search box.
E-commerce sites often use both implementations in the same search box, while information-based sites tend...