Explain a passage in plain language, without leaving the paper
Select a dense sentence, a formula's description or a piece of jargon, choose Explain, and get a short plain-language explanation based on the passage, the text around it and the paper's abstract. On the web and in the iPhone and iPad app.
Every field has passages that stop you: a term the authors never define, a method described in three compressed lines, a result that only makes sense if you already know the debate. You could open a search engine or a chatbot, paste the sentence in, and hope it guesses which paper you are reading. Or you can ask about it where it is.
Select the passage and choose Explain. A few seconds later you get a short explanation in plain language, written for this passage in this paper. It is on the web, including phone browsers, and in the iPhone and iPad app, for PDFs and EPUBs.
Ask for an explanation
On the web, select some text in the reader. The toolbar that appears for highlighting has an Explain button (1), next to the highlight colours and the note and dictionary buttons.
You can also explain a passage you have already highlighted: open the highlight's note card and choose Explain. On a phone browser, Explain is the fourth action in the selection toolbar, after Underline, Note and Define, and it is also in a saved highlight's sheet.
In the iPhone and iPad app it works the same way: select text in a PDF or an EPUB and tap Explain in the selection bar, or tap a saved highlight and choose Explain in its sheet.
What you get back
The explanation opens in a card in the corner of the reader, or in a sheet on a phone and in the app, so the paper stays where it was.
- The explanation is short, usually a paragraph or two, and written as a tutor would put it: what the passage means and why it matters in the paper's argument.
- What it cost (1). The line under the answer shows how many AI credits that explanation used.
- What to do with it (2):
- Save to note keeps the explanation with the passage. On a new selection it creates a highlight whose note starts with AI explanation:; on a saved highlight it adds the explanation below your own note, under the same label, so you can always tell your words from the AI's. It is not offered on highlights imported from Zotero, which are read-only.
- Ask in chat opens the paper's chat with the passage and the explanation already in the message box, ready for your follow-up question. Nothing is sent until you press send. It is in the desktop and tablet reader and, for PDFs, in the iPhone and iPad app; phone browsers do not have it yet.
- Copy puts the explanation on your clipboard.
What Explain reads, and what it does not
To write the explanation, ScholarThread sends the passage you selected, up to 1,500 characters of the text either side of it, and the paper's title, authors and abstract. That is enough for the explanation to know which paper and which argument it is about, without sending the whole paper.
Like ScholarThread's other AI features, it runs on Amazon Bedrock in AWS's EU regions, and your content is not used to train models. The privacy policy has the details.
Explain is there to help you understand, not to write for you. It will not produce text to hand in or answer an assessment question for you; it says so and explains the passage instead. Chat has its own safeguards, described in how the assistant stays on the right side of academic integrity.
What it costs
Explain uses AI credits, like chat. Pro includes a monthly allowance; on the Free plan you can buy a credit pack. Each explanation is charged for what it actually used, and the card tells you how much. If you run out, the card says so and offers Top up.
Every press of Explain is a new explanation and a new charge. If your connection drops while an answer is on its way, ScholarThread picks up the same answer when it reconnects rather than charging you twice. The pricing page has the plan details.
Explain needs an account: it is not available when you use the app without signing in.
Switch it off
Explain is on by default. To hide it everywhere, turn it off in Settings → AI usage, in the AI features card (1). In the app, it is in Settings → AI features.
Good to know
- Up to 2,000 characters at a time. For a longer stretch, explain it a paragraph at a time.
- For a single word, Define is usually all you need. Explain is at its best on a sentence or a paragraph, where it can use the surrounding text.
- It needs selectable text. A scanned PDF without a text layer has nothing to select.
- It needs a connection. If you are offline, the card tells you it could not reach the server, and Try again sends the same request when you are back.
If an explanation misses the point, select a little more of the surrounding sentence and try again, or take it into chat and ask a sharper question. And if something here does not match what you see, tell us.