NotebookLM now offers a 'video overview' as well as an 'audio overview'

The moment I heard this I wanted to try it out for myself so I tried it with the video on YouTube I had made when rehearsing for the JALT/EUROCALL joint webinar.

Here is the video of the rehearsal:

This is the summary created by NotebookLM:

Summary

This webinar rehearsal, led by Chris Fry, introduces educators to a method for providing instant speaking feedback to language students using AI tools. The primary focus is on Turboscribe AI for transcription and ChatGPT for comprehensive error analysis and improvement. Students, aged 13 and over with parental consent, can use free accounts to record their speech, receive a transcript, and then engage with a nine-step AI-powered feedback process. This process incrementally guides them from identifying and correcting basic errors to generating and listening to increasingly sophisticated versions of their spoken output, facilitating a gradual improvement in their language proficiency.

Here is the video overview created by NotebookLM based on just this one source:

Using an average of scores from Pearson's GSE Text analyzer and Text Inspector the transcript is about B2/B2+ 

Summary by NotebookLM

This source introduces an innovative, free two-part AI system that acts as a personal language tutor, designed to help learners achieve fluency in any language. The system addresses the common problem of lacking immediate feedback when practicing speaking independently, enabling users to receive instant, detailed feedback on their spoken language. This "AI language tutor" combines a transcription tool, like Turboscribe AI, to accurately convert speech into text, with a language model, such as ChatGPT, to provide comprehensive corrections and improvements. The process unfolds across three progressive levels: firstly, fixing obvious errors in grammar and structure; secondly, polishing phrasing to ensure natural, fluent expression; and thirdly, upgrading vocabulary to enhance expressiveness and sophistication. By systematically addressing these areas, the AI not only corrects mistakes but also significantly boosts a learner's confidence and control over their language acquisition journey, working for over 90 languages.

I then wondered how the video overview might change if I added two more sources.

1. My nine-step prompt revised to produce a smoother transition between the different levels of suggested improvements. 
   
   Summary of source by NotebookLM

   This source outlines a nine-step process for refining transcriptions, likely from an AI tool like Turboscribe, by systematically improving their quality. The core purpose is to elevate a text from its initial flawed state to a highly sophisticated version, moving through incremental levels of linguistic complexity and coherence as defined by the GSE and CEFR frameworks. Each step involves identifying and correcting errors, then progressively rewriting the text to incorporate more advanced grammar, richer vocabulary, enhanced logical structure, and greater detail, with all changes meticulously marked to show the evolution of the transcription.

2. A pdf showing the different steps and how to introduce them in different stages:

Summary of source by NotebookLM

This document outlines a nine-step process designed for improving transcription quality by systematically refining text. The methodology progresses through several "stages," beginning with identifying and correcting errors in an initial transcription. Subsequent stages focus on enhancing the language and structure of the text, first by rewriting half a CEFR level up with improved cohesion and vocabulary, then by further elevating the complexity, detail, and logical flow of the prose. The overarching purpose is to provide a structured approach for achieving increasingly sophisticated and error-free transcriptions.

Perhaps surprisingly the video overview based on three sources was actually shorter:

Using an average of scores from Pearson's GSE Text analyzer and Text Inspector the transcript is about B2 

Summary by NotebookLM

This source outlines an innovative method for transforming a personal device into an AI language tutor, offering immediate and tailored feedback on spoken language. It details a system leveraging two free tools, Turboscribe for accurate transcription and ChatGPT as the expert AI coach, to help learners progress from basic corrections to sophisticated expression. The core of this method is a "magic prompt" – a series of instructions that guides the AI through three stages: fixing errors, improving natural style, and levelling up language to more advanced forms. This personalised approach aims to build confidence and enhance learning by providing instant, customised feedback based directly on the user's spoken input.