Grouping Items into a set of Multiple Categories

Question

I have a list of items which we need to have users place into one of three pre-defined groupings. Looking for an efficient way of doing this. There could be anywhere from 2 to ~100 items but the groupings are static (3 in total). Couldn't upload an image, but let me know if I can better explain.

Any thoughts?

Answer 1

You should first of all consider supporting the sorting of your items on various relevant (and displayed) attributes to allow expert users to easily create contiguous blocks of items (e.g., via shift-clicking) to be categorized at once.

In any case, there are two basic options:

Radio Buttons

You can display the 2 to 100 items in a scrolling table with three radio buttons for each item to select the category. With one click to make a category selection, it’s more efficient for single items than drag-and-drop or selection-and-command-buttons. It also makes for among the most compact presentations. With radio buttons you can also have a default selection, which may be desirable if it’s necessary to ensure all items end up in a category (any category). If not, you can have a fourth radio button for No Category to allow users to de-categorize any item at any time.

The user should be able to sort on the radio button group (e.g., by clicking the column header for the group) to see all items together in the same category -including all the No Category items that still need to be categorized.

If there are sometimes contiguous blocks of items that go in the same category, then consider also a pulldown menu, along with a context menu, that allows users to set all items in a selected block to the same category. Alternatively, you may want to consider multi-attribute copy-and-paste to support this.

Multiple List Boxes

You can have a separate table or list box for each category, where the user moves an item to the category with a command button. Drag and drop may also be supported for categorizing (and re-categorizing), but because of its low discoverability, it should be considered to be an expert shortcut.

Multiple list boxes should only be considered if only a fraction of your items end up in any category (like selecting email addresses from an address book for the To and CC fields). In this situation, it easier for user to see if they’ve categorized all they should have categorized. However, it sounds to me like your users need to categorize all items, so they're probably better off with the radio buttons option.

Generally, you should have a separate list box for each category, not re-use the same list box. Re-using increases the chance of user error from when they don’t notice the current category setting for the list box. It also decreases efficiency and flexibility, either forcing the user to frequently change the current category (click-click) or adjust their work flow to fill one category then switch to fill the other category. Finally, three separate list is easiest for tracking the items in all categories with a single glance, which is the whole point to having separate list boxes.

Answer 2

I think if you have the option of drag'n dropping, and allow multiselect, then that's an efficient way to go. The user would simply click on the items he wants to move, and then drag them into the desired group.

Answer 3

I think you should avoid having your users to select/categorize each item individually. Even making a multi-selection in a ~100 element list is asking for trouble (imagine you painstakingly ctrl-clicking 36 items, and then click on the 37th with no key held down...)

Is there any way you can filter these items, or sort them, so you can operate on the visible items? Or at least make selecting them easier, avoiding too many clicks?

Are you keeping all these items in one list, even after categorizing? Maybe you can move them out of the way (in another list, hide them, sort them to the bottom, move into subfolders, ...) so the user can see what's still to be done.

Answer 4

This is probably a good example of where drag-n-drop really shines together with multi-selection as Pablo mentions.

Another possibility is that you could create two adjacent list boxes representing uncategorized items on the left and ones part of a category on the right. Furthermore a dropdown box or something similar could be used to specify the active category represented by the right side listbox. In the Microsoft Windows 7 UX Guide this is referred to as a List Builder.