Google.com has tabbed browsing in its main search results template (although they do not design them as such). However, my UX colleagues believe that these tabs are not used much, and believe that this is common for all search UIs: people are not making use of tabbed browsing in the result templates.
My question: Is this backed by real research?
I've tried to google the problem. I found a fairly recent publication by Norman Nielsen on best practices for eyelashes in general and also a meta-analysis that indicated that tabbed browsing caused problems for some library search UIs. But this study does not answer if there were problems in the individual implementations or if the strategy of tabbed browsing in the results templates as such is wrong. Therefore, references to more research would be appreciated.
It goes without saying that it would be great if the default relevancy was so good that we would not need filters or tabs. In addition, in our ongoing project, we are using group results to reduce our dependence on the tabs. However, they remain a key concept in our current templates and we would like to identify if usability problems are tactical (implementation) or strategic (conceptual).
I include the screenshot above (slightly written) as a bonus. The users tested it and not all the users could make productive use of the tabs. At that time we did not have the result counts, which we hope will produce a certain "aroma of information". We are also considering adding borders and background colors to the eyelashes, as recommended by Jacob Nielsen.