Vocabulary

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A practical dictionary of 512 AI, machine learning, mathematics, and programming terms from HerbDev’s AI Vocabulary app. Start with a definition, explore an example, then follow the concepts behind it.

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Perplexity

Natural Language Processing · Level 2 of 5

Perplexity

The exponential of average negative log probability under a sequence model.

Lower perplexity means higher assigned probability on comparable tokenized evaluation data.

Example

Two models using the same tokenizer are evaluated on held-out text.

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Audio transcript

Perplexity. The exponential of average negative log probability under a sequence model. Lower perplexity means higher assigned probability on comparable tokenized evaluation data. For example: Two models using the same tokenizer are evaluated on held-out text.

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