Table 5.

Results of error analysis-chemotherapy start date.

Types of Error	Subtypes of Error	Number, %	Total No.
Human errors	None	6, 28.6%	21
Outside material	None	5, 23.8%
Dictionary insufficiency	None	2, 9.5%
NLP rules	lacking semantic inference for dates	7, 33.3%
	Heuristic rules for unprecise dates	1, 4.8%