# Ambiguity using a Sortable List of Dates

I have a basic vertical list of dates which can each be dragged to reorder the list, with the goal being to allow the user to change the order and date of each item to their liking.

An example list of reorderable dates is:

1. November 2: some text here
2. November 2: more text here
3. November 3: some more text
4. November 4: even more text

I have noticed one use case which is proving problematic:

• Dragging an item in between two dates which are the same = no problem
• Dragging an item in between two dates which are different = ambiguous
• Dragging an item to the start of the list = no problem
• Dragging an item to the end of the list = no problem

It is this 2nd use case which is the problem: when dragging to a destination which is in between two different dates, we cannot be sure which date the user is intending to choose.

So in the above example list, I would be dragging item #4 in between items #2 and #3. As you can see, it becomes ambiguous to determine the new date for the item.

Any ideas on how to combat this problem would be much appreciated!

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To clarify: dragging the item to a new position changes the date on that item? – Erics Nov 3 '11 at 5:51
yeah that's correct - so when item #4 is dragged between #2 & #3, the new date could be either November 2nd or 3rd. – Ben Nov 3 '11 at 6:16
What are you expecting to happen if there's a hole in the dates? (What if you drag an item between two events on Nov 10 and Nov 14 and there are no events on the 11th, 12th, or 13th)? – Patrick McElhaney Nov 3 '11 at 11:34

## 2 Answers

I think the problem is conceived by the fact that you see the combination of a date and the text as 1 thing.

Let me make a suggestion: make it look a bit more like a calendar. Quick mockup:

In this example the red squares can be dragged and there is no confusion of which date an item will get since the whole day is a "drop-zone".

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That's a great suggestion, although two conditions in my particular situation make it impractical: 1) the order of multiple text items within a given day is important 2) I have a fixed amount of width to play with in the design. – Ben Nov 3 '11 at 10:37
To counter nr 2: you can also arrange the items vertically. To counter nr 1: How is the order of the items determined? Does the computer sort these items (alphabetically, or based on something else), or does the user need to choose the order? In that case you can just have drop zones between every item. – Bart Gijssens Nov 3 '11 at 10:47

I dont see the ambiguity.

If users are dragging to reorder, and the dates are derived from that, then the expectation would be for the item to receive a date somewhere between the two.

However, if you wish to drag in order to choose a specific date then simple list reordering is not the right tool. Rather you need to be able to drop items into some specific box that says "nov 3", for example.

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Thanks for your view, I agree that a simple list with default reordering behaviour is not ideal. I'm now thinking that allowing reordering within a given day will be simple as there will be no date change, and dragging outside this "same date" region will cause the date to be changed to whichever to same as whatever item it is dropped on. – Ben Nov 3 '11 at 10:41