Until I read your question, I hadn't even noticed the totals at the top. That alone indicated to me that the subtotals on the top are not clear.
Additionally, here are some reasons why your totals should be placed at the bottom:
- Users read table data from top-to-bottom.
- Totals are an equation. Relating to the previous point, the user will best interpret a total if they see the components first. A total before the data is like writing out all equations with the answer first, such as: 4 = 2 + 2. Although this is readable, we can process 2 + 2 = 4 easier.
- "Vegetables" and "Fruit" act as summarizing labels when the data is expanded out, and thus, doubling their use as amount totals might confuse the user.
However, there are some scenarios when you might consider leaving the totals up top:
- Lots of data. If you have hundreds of rows, being able to quickly identify the total before all the entries might be useful.
- When collapsed. Because "Vegetables" and "Fruit"
act as summarizing labels, it makes sense to place those totals where
Here are some simple interface changes I came up with as a compromise:
- The totals are placed at the bottom, and can be identified more easily. You could even place a "Totals" label on this row, possible under the Type header.
- To make this interface even more clear, consider placing the Amount
column on the far-right, that way users read the data as Quantity x
Rate = Amount. The total would then be placed at the bottom-right of each type, increasing readability further.
- Assuming the following interface is similar to yours when the rows
are collapsed, this interface still allows for the user to see the
totals on the type.
Hopefully the above suggestions help!