I know there is a lot of similar questions to this stating when you should or shouldn't open links in new tabs. But what I want to understand is if someone who's not a power user will open a link in a new tab if necessary? Or will he open it in the same tab and click back a bunch of times?
You need to research your audience group with the following questions in mind:
- How familiar are they with the steps involved in opening a link in a new tab?
- If they do know how, under what circumstances will they do so? Will you run into them with your site/application?
I work for a company with an online project management product. In my recent shadowing sessions with users in creative agencies, they frequently open multiple items in our system in different tabs. They do this because they want to compare and modify items of the same type in the system. They lose their frame of reference when they need to use the back button to go back to the listing page to click into the other item. That's why they open multiple tabs. (sidenote: we can design the system so they don't need to do this, but that's a different issue.)
Now you may say they qualify for "power users", but most of our users in that particular role does this. They uses the computer a far bit in their work, but are by no means a wiz. The only keyboard shortcuts they know are Copy & Paste. They use the mouse to move around on a web form instead of tab key. So I don't see them as "power users". Yet they open lots of tabs.
Wrap-up: It depends on your audience group and what they are trying to accomplished. If it's way more work to use the back button repeatedly and they know how to open links in new tabs, they'll probably do that instead.
Actually, if you (and many others) keep asking this it's because the answer is "no".
You don't trust your own observations because it's not a scientific way to measure the world.
And so do the many others asking the same thing.
But in this case we are the evidence. None of us is witnessing reams of browser users opening links in new tabs because almost nobody does so.
I myself do it, but this is because I'm old, and when I started with the new tab thing (initially it was new page in Netscape) I did it to avoid having to wait the page reload over the slow Internet of the nineties.