Codependent (Filterable) Categories - Beyond the Dropdown

Question

This is my first question here, I hope this makes sense.

On a website, I am trying to represent Businesses and allow them to be filtered (AJAX) by 2 or more Taxonomies: Activity Type, and Community.

My instinct is to use a dropdown because it can hold many terms in a small amount of space. However, this presents a challenge as the selection process should not be linear (i.e. Choose Make => Ford; Choose Model => Focus;).

If a user chooses a Community, the choices for Activity should be limited to only where Businesses intersect (AND) with the chosen Community. Likewise, if Activity is selected first, the available Communities should reflect only those that contain Businesses which hold the taxonomy term chosen for Activity.

The dropdowns could modify one another, and some descriptive text (either added above, or alongside each term) could indicate the list is reflective of the other chosen information. But will this make any sense to the user?

Choose Community => Sycamore
Choose an Activity in Sycamore => Dining

or

Choose Activity => Sports
Choose a Community for Sports => Sycamore

I plan to have the list of businesses update dynamically as each filter method is applied/removed (paginated).

So what is the best method to handle multiple taxonomies in terms of aesthetics and extensibility while still making sense to the user?

Answer 1

You could try the following idea. There are clear selection and dependencies indicators. Also user can choose any item anytime and dependencies will be re-drawn.

.

After selecting both parameters, the results are displayed.

Answer 2

I feel you are trying to provide a solution appropriate for hierarchical structures (taxonomy, 1 to many, child-parent):

to what is really a graph (many-to-many, ontological) structure:

The latter suggests that you should treat your items less as a taxonomy (categories) and more as facets (tags). Which in turn will suggest that filtering is the solution. So:

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One advantage of this solution is that upon selection, the filtering is visible to the user (feedback loop) unlike with drop downs.

Also, while I'm not sure the logic of the system is such, seems to me it may be that users can select more than one activity (and possibly more than one community).