Changing the location or function of a control on a user is normally something that is frowned upon, and with good reason. But take this situation as an example:

Users need to specify a number items from a list, which they want to associate with a thingy. Some users may have only a few items, while others may have dozens or hundreds.

  • If there is only one item, the association could be made for the user, with no controls given.
  • If there are 2-5, perhaps a set of check boxes would be sufficient or appropriate to choose a subset.
  • But if the user has 150 items, it might make more sense to use a "pillbox" or "tag input" box with autocomplete for entries; or perhaps a two panel "multi-select then add" UI would be more efficient, or maybe just a long table-format list with check boxes, or a list of checkable items in a scrolling window with a "Select All" option, or some crazy multi-select drag and drop doodad.

I'm not sure which of those would work best, the question is this: In the same UI is it ever ok to present ONE control to one user, and a DIFFERENT control to another user, maybe one with a different set of items? Would users get freaked out if they crossed the threshold and suddenly had a different control, or would it likely just make sense to them?

2 Answers 2


The controls/behavior should be consistent for 1 items or many - it will help your users develop the required mental model and perform the tasks more efficiently.

Changing the controls depending on the items available will become an additional memory load on users which they don't like. Don't force your users to remember two different controls for the same action. For example: When I'm forwarding a message to someone on WhatsApp (one or many) the controls remain the same.

  • Yes, but does that apply to a system that people will not have regular interaction with? Many of our users may only come and work in the UI every few weeks, or even less for this particular action, so that expectation that they will remember the control is not particularly high. The controls should be intuitive, but memorable may not be as critical.
    – Mattynabib
    Commented Feb 23, 2017 at 22:39

I like the idea of progressively enhancing the controls, but Dipak does have a point. You shouldn't use different select patterns.

I think you could stick with checkboxes and still have some progressive enhancement.
When the amount of items exceeds a certain threshold number you could add a searchbar that allows your user to filter.
Your users would loose oversight with such a long list, maybe not remembering what they selected already, but your "in-between step" of confirming before adding (at least, that is what I think you mean by "a two panel multi-select then add UI") might solve this.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.