Table 1. Mean character and word error rates (with 95% CIs) for the handwriting BCI across all 5 days.

“Raw online output” is what was decoded online (in real-time). “Online output + offline language model” was obtained by applying a language model retrospectively to what was decoded online (to simulate an autocorrect feature). “Offline bidirectional RNN + language model” was obtained by retraining a bidirectional (acausal) decoder offline using all available data, in addition to applying a language model. Word error rates can be much higher than character error rates because a word is considered incorrect if any character in that word is wrong.

	Character Error Rate [95% CI]	Word Error Rate [95% CI]
Raw online output	5.9% [5.3, 6.5]	25.1% [22.5, 27.4]
Online output + offline language model	0.89% [0.61, 1.2]	3.4% [2.5, 4.4]
Offline bidirectional RNN + language model	0.17% [0, 0.36]	1.5% [0, 3.2]