As Bob said, thank you for all of your hard work on this! The ability to assign weights to all categories and/or items on one screen is a big functionality improvement.
I agree with Bob's assessment about the interface: interface2 is very preferable to interface4. The layout is closer to the current layout, which is what our instructors are now used to. As you mentioned, this layout is very intuitive and makes it easy to see what items and categories are nested within other categories.
I agree with you that a string of unfamiliar icons is not the correct way to address this issue. Instead, I would argue that showing all of the category options on a single page is unnecessary and overwhelming. The vast majority of instructors do not need those options, so it would make more sense to me to create a separate report with all of those options instead of jamming them onto the default Categories and Items page.
I have been working with a group of instructional technologists from other institutions on gradebook usability. Here are some usability issues we've found with the current patch (interface4):
1) The "weights and extra credit" column is confusing. There is no visual indication of which text boxes are for weights and which are for EC. I don't think it makes sense to lump these two options together. I would argue that EC does not belong here at all. (As I mentioned above.)
2) There is no visual indication in the weights column of which items/categories are nested inside other categories. It should be effortless to see which items are being weighted against each other; instead, it looks like each item is weighted against everything else on the page.
3) This is a minor cosmetic thing, but the font is larger than necessary, and larger than the rest of Moodle. I have to lower the font size in my browser to avoid horizontal scrolling.
Based on the above assessments, the things we'd like to see on this page are:
1) A more clearly defined tree structure, like the current core C&I interface or the interface2 screenshot. For me, the interface4 layout does not provide this.
2) The only additional options we'd like to see on the C&I main page are the aggregation method and the weight. It is advantageous to be able to set these from a single page because they are interrelated; the weights are relative to each other, so it is necessary to be able to set them on one page. The other settings (e.g. multiplicator) only affect the individual category, so it makes more sense to set those on that individual category's options page.
I understand Gary's desire for instructors to be able to work through the gradebook's calculations to verify that it is set up and calculating correctly. My instructors have been asking for the same thing. However, I don't think the current patch fits the bill, since the instructors would have to have the grader report open separately (or on paper) while they worked through the calculations. Instead, I would propose adding a column to the grader report (with a show/hide toggle) which shows the calculations the gradebook is doing as a formula. This would be much more useful to my faculty.
Thank you again for all of your hard work! I know it's difficult to balance everyone's needs and figure out an interface that works for everyone. We really appreciate what you're doing!