As much as I gripe about UX annoyances (and all manner of other annoyances), I really do try to look out for specific ways to improve. I don't come up with many, most likely because UX is hard and lots of people who are better at it than I am have spent a lot of time on the problem and come up with a lot of good ideas. Much of the low-hanging fruit has been picked, and so has a lot of the not-so-low-hanging fruit.
However, while grumbling at a particular web page today, I think I hit upon a good rule. I doubt it's new, because a lot of sites follow it (and see above regarding fruit), but a lot don't, so I'll put it out here anyway, for my vast audience, just in case.
Changing one setting on a page should only change the corresponding thing(s) on that page
For example, say I'm looking at statistics on farm production in US states. I can rank output by, say, yield per acre, dollar value, amount per capita and dollar value per capita. I can pick a specific list of states or crops. I pick corn and soybeans for crops and North and South Dakota, Nebraska, Kansas and Oklahoma for states. Up comes a nice table, initially sorted alphabetically by state. I change the sorting order to dollars per capita, from high to low. So far so good.
Now I decide to add wheat to the set of crops. On a well-designed page, I will now see the same data, for the new set of crops, sorted the same way as before. On all too many sites, I see the data for corn, beans and wheat, but sorted alphabetically by state, because that's how all tables start life. I changed one thing -- which crops I'm interested in -- but two things changed, namely the data being shown and the sort order. I only wanted one thing to change, namely the set of crops.
This is a small example, but I'd be surprised if you haven't run across something similar. As described, it's a minor annoyance, but as the options get more sophisticated, annoyance turns into unusability. If I've spent five minutes setting up a graph or chart of, say, crop distribution as a function of latitude, I don't want that all to go away if I decide to include Colorado or Iowa in my set of states.
This is not to say you can't have settings with wider-ranging effects. If there's a tab on the page for, say, trends in agricultural veterinary medicine, I wouldn't expect my graph of crop production to stick around (though I would very much like it to still be there if I go back to its tab). That's fine. I changed one setting, but it's a big setting and the "corresponding things" that need changed are correspondingly big.
Again, this is nothing new. For example, it fits nicely into considerate software remembers. Still, it's often useful to find specific examples of more general principles.
