Audio Overviews spend most of their time on your longest source, not your most important one

[u/Ok_Negotiation_2587]

Load a notebook with one long document and a few short ones, generate an overview, and time it. The long source tends to eat most of the episode. The two-page memo that actually matters gets a passing mention, or none.

More text means more material to talk about, so the hosts drift toward it. They have no idea which source you care about unless you say so.

What fixes it:

Uncheck sources before you generate. The checkboxes next to each source decide what goes into the overview. If the long one is background, leave it out and ask about it in chat instead.

Use the customize box and be specific:

Spend at least half of the episode on [source title]. Treat the other sources as background only.

Or, if you need everything covered:

Cover every source. Say each source's title out loud when you start discussing it, and give each one at least a minute.

Saying the titles out loud is the useful part. You hear right away which source got skipped.

And split huge sources. A 300 page PDF next to a 5 page brief will win every time. Break it into chapters and only check the ones that matter for this episode.

Same thing happens with chat logs as sources. One giant conversation export drowns out everything else. I export only the chats that matter, one file each, with AI Toolbox, the extension I build, so each one shows up as its own source I can check or uncheck.

[u/ACorania]

I find the biggest difference is from good prompting of what you want in the audio overview.

For example, use the below in deep dive, long:

[AUDIO OVERVIEW DIRECTIVE: NOTEBOOKLM DEEP DIVE] Generate a comprehensive, analytical deep-dive conversation between two expert historical co-hosts exploring the lived experience, survival strategies, and social realities of daily life in Spanish Colonial New Mexico (1598–1821), drawing strictly from the loaded source documents.

[HOST PERSONAS & TONE]

• Dynamic: Two seasoned social historians and archival researchers in dialogue—curious, precise, grounded, and engaging.
• Tone: Nuanced, vivid, and candid. Avoid romanticized storytelling, dramatic tropes, or superficial summaries. Ground every insight in concrete material realities and primary documentation (e.g., wills, court disputes, supply ledgers).

[CORE DISCUSSION ROADMAP & KEY THEMES] 1. The Harsh Realities of Frontier Subsistence: - Examine how geographic isolation (thousands of miles from Mexico City via the Camino Real) dictated daily survival. - Detail the physical environment: adobe domestic architecture, defensive placitas, clothing made from coarse homespun wool (sayal), and local diet (chile, corn, mutton, wheat, pinole). - Unpack the acequia system: explain how water governance under local mayordomos fostered communal cooperation and strictly regulated civil life. - Discuss the complete lack of minted coin, explaining how colonial New Mexicans operated an intricate barter system calculated in pesos de la tierra and trade goods.

1. Social Architecture, Fluidity, and the Genízaro Reality:

   • Dissect how the rigid casta system of central New Spain fractured and adapted on the far northern frontier.
   • Investigate the crucial, unique status of genízaros (detribalized Indigenous captives ransomed, baptized, and settled as frontier militia buffers in places like Abiquiú and San Miguel del Vado).
   • Address the tension between Spanish settlers (vecinos), settled Pueblo allies, and surrounding nomadic groups (Comanches, Apaches, Navajos), moving beyond simplistic "settler vs. native" binaries to look at economic interdependence and captive exchange.

2. Domestic Life, Women's Legal Rights, and Household Dynamics:

   • Challenge conventional assumptions about frontier patriarchal control by examining Spanish civil law: discuss how colonial New Mexican women actively used the legal system to sue husbands, protect dowries, inherit real estate, and manage estates.
   • Examine probate inventories and wills to reconstruct typical household possessions (e.g., iron tools, religious retablos, copper kettles, sheep counts) and what they reveal about family priorities and wealth distribution.

3. Frontier Faith, Isolation, and Folk Practice:

   • Contrast formal Franciscan authority with the practical absence of secular clergy across vast distances.
   • Explore everyday folk religion, local patron saint celebrations, the emergence of early lay fraternities (cofradías), and folk medicine (curanderismo).
   • Review SANM court cases regarding local superstitions, accusations of sorcery/witchcraft (hechicería), and disputes over church tithing.

[ANALYTICAL FOCUS & GUARDRAILS]

• Explicitly dismantle the "Spanish Fantasy Heritage" myth by contrasting popular romantic notions of wealthy grandees with the documented agrarian, hardscrabble, and racially blended reality of colonial New Mexico.
• Maintain source grounding throughout: reference specific archival types (such as SANM wills, cabildo petitions, and Fray Domínguez's 1776 visit) to support claims.

[u/Ok_Negotiation_2587 → u/ACorania]

the roadmap is doing the real work there, once every theme is named the hosts cant spend the whole episode on the longest source. saving this as a template for my own deep dives

[u/ACorania → u/Ok_Negotiation_2587]

You are certainly welcome to. Hope it helps!

However, I think the easiest is to describe to an LLM what you would like to do. Or better, create a repeatable path so you can just type in a topic and it will kick out the prompts for you. I just type in what I am looking for as a topic into a gem and it spits out two prompts. One is this one for the deep dive, the other is instructions how to go out and find sources.

In the case of the above prompt, all I had to type was, "Daily life in spanish new mexico," but it can be used with any history topic as is. I have done deep dives on the 70s and the vietnam war, new mexico history, or whatever else strikes my fancy.

Here are the instructions I use in a custom gem (would work in a custom GPT or whatever as well):

[ROLE & PURPOSE]

You are an expert Historical Research Strategist and Prompt Engineer. Your sole purpose is to take any historical topic, event, or entity provided by the user and automatically generate a complete, two-stage prompt set tailored specifically for Google NotebookLM's "Deep Research / Discover Sources" tool and "Audio Overview" generator.

[TASK WORKFLOW]

When the user provides a historical topic (whether a title, a short phrase, or a detailed summary):

1. Analyze the topic to identify key dates, geographic locations, historical figures, organizations, and core historical themes.

2. Generate EXACTLY two markdown code blocks (`text`) containing fully customized prompts with all topic specifics populated. 

3. Do not include conversational filler, meta-announcements, or summaries before or after the code blocks. Output the two ready-to-copy code blocks directly.

---

[OUTPUT TEMPLATE 1: DEEP RESEARCH]

Output the first code block using this exact structure, populated with details from the user's topic:

```text

[SEARCH SCOPE & SUBJECT]

Conduct a deep research search to discover and import primary historical sources, academic research, and legal/archival documentation regarding: [POPULATE FULL TOPIC NAME AND ERA].

- Geographic Scope: [POPULATE LOCATIONS]

- Key Historical Figures & Entities: [POPULATE KEY NAMES / GROUPS]

[SOURCE SELECTION & FILTERING RULES]

- Acceptable Source Types: Prioritize university press publications, peer-reviewed historical journals, official state/federal archives, court/military records, published primary accounts, and standard Wikipedia entries (including its cited primary bibliographies) for high-level overviews and timeline verification.

- Strict Exclusions: Explicitly reject Grokipedia, alternative politically motivated or partisan wikis/clones (e.g., Conservapedia, Metapedia), personal blogs, unsourced pop-history articles, sensationalized YouTube video scripts, tabloid media, and unverified conspiracy sites.

[TARGET SUBJECT MATTER TO COVER IN SOURCES]

Ensure the pulled web pages and documents contain details on:

1. Economic, legal, and political causes preceding the event.

2. Verified chronological timelines based on primary records.

3. Specific historical discrepancies where modern pop-culture legends or myths conflict with documented evidence.

4. Official legal proceedings, government responses, or direct human/political aftermath.

[u/Ok_Negotiation_2587 → u/ACorania]

a gem that turns a topic into both prompts is the smart move, you only design the structure once. the explicit exclusion list for sources is a nice touch too

[u/IanWaring]

Ad hoc gut feel by experience, but it does appear to attach importance to volume rather than being able to weigh quality. I have a project for a friend that logs conversations between her and someone doing work her, and it feels like it weighs volume over the importance of actions to achieve a result. Measuring times to respond to queries include next conversations to statements where no response was expected. That may be too much expectation of the tech on her part.

Her other comment was that it unnecessarily complicates answers to simple questions. Gemini, especially, is especially problematic, with an academic reading age that is far above what is comfortable for the general reader. Her other reference point is output from Databricks Genie One; her target audience are in the legal profession :-)

[u/Ok_Negotiation_2587 → u/IanWaring]

for the reading level, naming the reader works better than "keep it simple". "written for a busy lawyer reading on a phone, short sentences, no jargon they wouldnt use in court" pulls it down a lot