Reference Tooltips (stylized as "ReferenceTooltips") allows a user to roll over any inline citation to see reference information, instead of having to jump away from the article text. Yair rand is the initiator of the current discussion to allow inline citation pop-ups to appear by default rather than as a user preference.
At the moment, to enable ReferenceTooltips, any logged-in editor can go to My preferences → Gadgets → and click ReferenceTooltips.
Alternatively, any logged-in editor can manually install the script into their skin.js or their common.js page:
The proposal is to make this choice the default, so all editors have this gadget. Any editor who does not want it can then disable it in their preference panel.
At the time of writing, there were 17 support votes and 5 oppose votes for this proposal. The support votes are mainly driven by the fact that it would make references more usable. For example, instead of clicking on a reference and then jumping to the bottom of the page to find the reference, ReferenceTooltips enables the user to move their mouse over the reference and read the information. The oppose votes are compelled by the technical limitations of ReferenceTooltips and how the pop-ups would make the Wikipedia experience worse. For instance, enabling the reference to pop-up by mere hovering will cause pop-ups all over the place if an editor is just scrolling through a page. In addition, there are concerns that browsers will block the pop-up as an advertisement.
Some suggestions to avert a technical mishap are to only enable a reference to pop-up when the user clicks the inline citation. Still, all of the oppose votes believe that most editors won't use the reference tool and only researchers would be able to use this tool. The oppose voters believe that ReferenceTooltips should be left as an opt-in tool or gadget rather than being available by default as many editors would find it obtrusive.
In favour of supporting the gadget by default, an argument provided by Silver seren was: "Yes! This would be extremely useful, rather than having to hit back to go to the spot you were in the article before you clicked it. This way, [you] can tell beforehand if it's a reference you will actually want to click into. Furthermore, it lets you know directly which reference that number is referring to, without having to go to the reference list. [ReferenceTooltips] [h]elps you understand the narrative of the article and its references without a bunch of back and forth clicking."
A contention provided by Nageh opposing the proposal (but later moved to "Weak oppose/neutral") was: "The vast majority of unregistered readers give a damn about references. They just want their information and they are done. Also, popups can easily become an annoyance, and they usually annoy me, too, even though I actually like this tool. That does not mean it should be activated by default. Leave it as an opt-in tool, as it is now, and anyone registered and really interested in this additional functionality can easily activate it."