Microsoft’s turned on Researcher feature in the June update for OneNote. This feature is previously hidden now you the enable the feature with the latest update.
The latest update also brings find quotes, citable sources, and images to start your outline. This update is only for Fast Ring Insiders.
As per William Devereux tweet:
Hey Insiders! We just turned on Researcher in the June update for OneNote. Find quotes, citable sources, and images to start your outline. pic.twitter.com/PPYib9dsal
— William Devereux (@MasterDevwi) June 7, 2017
For getting this update you have to restart the app.