There are two other sorting methods (besides those you mentioned) I’ve seen which work pretty well.
Click To Move
The method used for ordering items in the Gallery web photo album works pretty well for ordering photos, and it should work just as well for any set that can be represented as a sorted group of clickable elements:
- Present your list of items as clickable elements.
- Clicking an element “selects” it, it is highlighted to indicate it’s selected.
- Clicking another item moves the selected item to a position just before the clicked item.
- Repeat until all items are in the desired order.
- A dummy item is shown at the end of the list for moving items to the end.
This is slightly easier to use than drag-n-drop as it requires less dexterity, and you don’t have to hold down the mouse button while you figure out where you want to “drop” the item.
The method could easily be extended to allow selection of multiple items (via shift-click or similar) which could then be placed in a new position in the same way.
Provide Order Numbers
Used by Netflix and some internal apps I’ve worked with. This works best if your users have a concrete idea of exactly what the numeric order should be (used when working with lists of instruction steps in our internal app).
- Present your list of items one per line.
- Provide a text entry box next to each item where the order number is displayed, starting with 1.
- The user changes the order numbers in the text fields as desired.
- If multiple items are given the same order number, they are placed next to each other.
- Provide a button to “apply” the sort in JavaScript so that the user doesn’t have to submit the entire page to see the re-arranged list. This makes it easy to work in increments.
Edit: A couple of additional thoughts on Drag-and-Drop. You might have used these before or not, but there are a few things that can make drag-and-drop more forgiving and easier to use:
- Highlight the area where the item will appear when dropped. For example, show a prominent horizontal line between the two existing items where the item will be inserted if it is dropped.
- Ghost the draggable item as it is dragged so that it’s obvious what’s being moved, rather than using a generic “dragging” cursor. This works best if the items being dragged are still legible if shown on top of one another with transparency.
- Make sure the target areas where the draggable can be dropped are sufficiently large. Larger areas can be helpful for people who have trouble with the required coordination.