It depends. But mostly bad
John Colby's from Birmingham City University arguments on why pop-ups are bad:
- Because people are warned about them (http://www.bbc.co.uk/webwise/guides/about-popups)
- Because of their association with scams, viruses, malware, sites using popups are 'less trustworthy'
- Users with sight or cognitive problems (http://soap.stanford.edu/show.php?contentid=47)
- (And personally) if they insist on using popups I'll go away.
Richard from Userite remembers us that:
with Charles McCathieNevile from Opera adding:
...that many users have pop-ups blocked by default now, so won't actually see it even if they are not blind.
Harry Loots of the IEEE has a point when he says:
If it will supply useful information to the user, then don't kick against it, but make sure that the feedback / information so provided is accessible. For example, if the pop-up is used to confirm the product has been added and the user's browser does not support scripting/popups, a physical line of text may be displayed to confirm the product has been added (which can be hidden in the view seen by users who get the popup)
When a client asks for a specific design element, one needs to wonder where this need came from in the first place.
In the case that the client is not satisfied with visibility of system status. Try
- Improving titles and labels
- Adding non-obstructive instructions
- Providing feedback in an alternative way (as Harry pointed out), additional confirmation page always helps
- Keeping elements and its status (e.g. shopping cart belongs to the top right corner) in its user-anticipated location
- Using visual cues to show what just happened