bert-encoder-only-cannot-generate-text

IN premise — summaries/2026/08/24/wiki-BERT_language_model-chunk-1.md

Created 2026-08-24T17:11:06+00:00

BERT's encoder-only architecture cannot naturally generate text; using multiple [MASK] tokens as a generation mechanism constitutes dataset shift and degrades performance.

Summary

BERT was built to read and understand existing text, not to write new text, so forcing it to produce sentences by filling in blank slots is asking it to do something it was never trained for. This means any system relying on BERT for text generation will underperform compared to models designed from the ground up to create text.