Dynamic or user-initiated filtering?

There are two main types of filtering interfaces:

• Dynamic filtering updates results automatically as a user makes each filtering selection.
• User-initiated filtering where the user makes some selections and clicks an update button to see new results.

Which approach to use often comes down to data and performance issues (sometimes dynamic filtering isn't feasible or advisable from a technical standpoint, particularly where users are likely to select multiple filtering criteria).

Endless Shoes and Handbags is an example of dynamic filtering; Hotels.com employs user-initiated filtering.

Interestingly, Tripbase gives the user a choice. By default, the site uses dynamic filtering. But users can override that default by de-selecting the "auto-submit" option.