NotebookLM Explained My Own Project Better Than I Could

Key Takeaways

• NotebookLM can summarize scattered project notes and help you re-enter a dormant project without re-reading everything
• The AI's 'source grounding' approach means it only knows what you upload, reducing hallucinations
• Prompts like 'What questions does this project leave unanswered?' reveal gaps you missed

Saikat Basu has been writing a book for longer than he'd like to admit. His notes live in an Obsidian vault: chapter outlines, themes, reference books, saved tweets, half-formed ideas. After weeks away from the project, returning felt like meeting a stranger. The context had evaporated.

So he tried something different. He fed the whole mess into Google's NotebookLM and let the AI onboard him into his own work. The result? A clearer overview in minutes than he'd get from hours of manual revision.

What NotebookLM Actually Does

NotebookLM is Google's AI research assistant with one key difference from ChatGPT or Claude: it uses 'source grounding.' The AI only knows what you upload. It won't hallucinate facts from the internet or mix your project with general knowledge. Every answer cites the specific document it came from.

“NotebookLM becomes an expert on your sources... you can trust the answers, since your sources are cited in-line.”

— Google Official Blog

This makes it useful for a specific problem: you have a pile of notes, documents, or research, and you need to understand what's actually in them. Not what the internet says. What you wrote.

The Re-Entry Problem

Basu uploaded his rough chapter notes. Within seconds, NotebookLM generated a summary of the entire project. Instead of re-reading dozens of scattered documents, he could ask direct questions: 'What is the core theme of this book?' or 'Which chapters focus on creativity and boredom?'

The summaries weren't perfect. They occasionally flattened nuance or merged ideas that deserved separation. But as a re-entry point after weeks away, it beat re-reading ten documents from scratch.

The key: upload all your source documents before generating a summary. NotebookLM's overview improves when it has more context. PDFs, Google Docs, and plain text files all work.

Finding the Gaps You Missed

The real value came from using prompts as probing questions. A simple prompt like 'What questions does this project leave unanswered?' sent Basu down research rabbit holes he hadn't anticipated.

In his book project, NotebookLM flagged that several chapters referenced an emotional framework he'd mentioned early in his notes. But he'd never actually defined it. The AI caught an inconsistency he'd been blind to for months.

Another useful prompt: 'Find contradictions in these notes.' When you're deep in a project, it's easy to hold conflicting ideas without noticing. The AI has no emotional attachment to your work. It just points out where you said one thing in chapter two and the opposite in chapter seven.

The Obsidian-to-NotebookLM Workflow

Basu's notes lived in Obsidian, a popular knowledge management app. NotebookLM can connect to Obsidian directly, or you can export your vault as PDFs. The community has developed a hack: export your entire digital vault into single PDFs to give the AI a 'total brain dump' of your creative history.

One rule matters: keep each notebook focused on a single project. NotebookLM works best when all the sources relate to one another. Mixing your book notes with your tax documents won't help.

Audio Overviews: Listening to Your Own Research

NotebookLM's breakout feature in late 2024 was Audio Overviews. The tool can convert your uploaded documents into a realistic AI-generated podcast. Two synthetic hosts discuss your research, explain the key points, and highlight connections.

The feature drove massive adoption. NotebookLM saw 201% month-over-month traffic growth during the Audio Overview surge, reaching 31.5 million monthly visits in October 2024. Users report listening to their own research while commuting, which turns dead time into review time.

Five Prompts That Actually Work

Reddit users in r/productivity have tested hundreds of prompts. These five consistently surface useful insights:

1. 'What is the core argument or theme across these documents?'
2. 'What questions does this project leave unanswered?'
3. 'Find contradictions or inconsistencies between these sources.'
4. 'Which ideas appear most frequently, and which only appear once?'
5. 'If I had to explain this project in two paragraphs, what would I say?'

The community calls these the '5 Essential Questions' prompt set. They work because they force the AI to synthesize across documents rather than summarize one at a time.

Limitations to Know

NotebookLM isn't magic. It flattens nuance. It sometimes merges ideas that should stay separate. It can miss the emotional weight you intended behind a section.

And it only knows what you give it. If your notes are incomplete, the summaries will be incomplete. Garbage in, organized garbage out.

“NotebookLM isn't trying to be just another flashy LLM wrapper. It's trying to fundamentally change how we think about knowledge work.”

— Steven Johnson, Editorial Director at Google Labs

But for the specific problem of re-entering a dormant project, it solves something real. The time away exposes gaps in your thinking. The AI just finds them faster than you would.

Frequently Asked Questions

Can NotebookLM connect directly to Obsidian?

Yes. NotebookLM can connect to Obsidian directly, or you can export your vault as PDFs. Many users export their entire vault into single PDFs for a 'total brain dump' approach.

Does NotebookLM hallucinate like other AI tools?

NotebookLM uses 'source grounding,' meaning it only knows what you upload. It cites the specific document for every answer. This greatly reduces hallucinations compared to tools that draw on general internet knowledge.

What file types does NotebookLM accept?

NotebookLM accepts PDFs, Google Docs, and plain text files. Upload all your source documents before generating summaries for best results.

Is NotebookLM free to use?

NotebookLM is currently free to use. It's part of Google Labs and requires a Google account to access.

What are the best prompts for NotebookLM?

Effective prompts include 'What questions does this project leave unanswered?', 'Find contradictions in these notes,' and 'What is the core theme across these documents?' These force the AI to synthesize across sources rather than summarize one at a time.

Source: MakeUseOf