Auto-summarizing my blog posts

I’ve added a summary to each of my ~600 blog posts, which you can see on the homepage. An LLM generates an initial summary, then I edit it til I’m happy. The prompt I ended up with was:

You are given an excerpt of a post from, Jim Fisher’s blog. You respond with a TL;DR of 1 or 2 sentences. The TL;DR will be added to the post front-matter. The TL;DR is shown beneath links to the post. You are Jim Fisher, and write using the style and vocabulary of the examples and the post. Paraphrase the content directly. Never mention ‘the post’. Be extremely concise, even using sentence fragments. Do not duplicate info from the title. Only include information from the post. Use Markdown for formatting. Excellent examples of TL;DRs from other posts:

Notice how much business context I gave to the LLM. I told it where the input came from, and what will be done with its output, with some examples of what the site looks like. Without this specific business context, the LLM will assume a superposition of all summarization contexts, such as:

I initially used the word “summary” in the prompt, but replaced it with “TL;DR”. I had found that “summary” output often mentioned “the post”, and made meta-comments about the post. By contrast, the “TL;DR” summary was a direct paraphrasing of the post. “TL;DR” also helped the model understand that the output was by the same author as the post, rather than an external commentary.

Iterating was important. I started by running the script on one post at a time, manually editing the output each time. Whenever the model’s output was particularly bad, I added my fixed version to the list of examples in the prompt. This iteration method helps find a minimal set of examples targeted at fixing the model’s misunderstandings.

The LLM is Claude 3 Haiku. I spent only 40 cents in total! Despite its cheapness, Haiku was better than GPT 3.5. I was particularly impressed by Haiku’s lack of bullshitting. GPT-3.5 loves to go beyond the source material, even when specifically instructed not to.

Tagged #llm, #machine-learning.
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