Page Previews
Since our UI relies a lot with Wikipedia entities, wouldn't it be nice if our UI offered page previews like they now have on the Wikipedia website. A quick Google search revealed a variety of existing solutions for implementing previews of Wikipedia pages in other pages. None of the implementations I found are trivial.
TL;DR
It's tricky to implement. Let's test whether people really need this. The current solution (short text descriptions in popup) isn't very fancy but works for now and might even be sufficient in the long term.
Testing desirability
We should test whether our users would actually appreciate such a feature before jumping to solutions. Asking some test users won't hurt.
Current state: Descriptions from Wikidata
Currently, our UI doesn't offer page previews but it does offer descriptions of entities, available through the popup-megamenu. We get these entity descriptions (along with the names of entities) from the Wikidata API. The descriptions tend to be very short, which is nice for the purpose of including them in the wiki-chunk popup menu. Based on initial self-observation, descriptions can occasionally be useful for disambiguation (e.g. which John Cage are they talking about?) or to refresh the learner's memory. However, they are sometimes too brief and incomplete to function as proper definitions of an unfamiliar concept. Besides, some entities appear to have no description.
Get content from Wikipedia
Presumably, it might help users to get proper definitions or content summaries similar to the popups on Wikipedia. To implement something this, I see two options:
A: Build our own previews
We could to call the Wikipedia API, in addition to the Wikidata API, in order to get text (multilingual) and images (if available) as they appear on the page. These posts explain how:
https://stackoverflow.com/questions/8555320/is-there-a-clean-wikipedia-api-just-for-retrieve-content-summary
https://stackoverflow.com/a/43748047
B: Use an off-the-shelf solution
I won't list all the options here because we should test desirability first and clarify requirements if any.
Besides, Wikipedia page previews are a fairly new and hot topic. More solutions might become available while we're testing and working on other stuff.