Table A.1.

NASA-Task Load Index Subscales

	Endpoints	Description
Subscale
Mental demand	Low/high	How much mental and perceptual activity was required (e.g., thinking, deciding, calculating, remembering, looking, searching, etc.)? Was the task easy or demanding, simple or complex, exacting or forgiving?
Time demand	Low/high	How much time pressure did you feel due to the rate or pace at which the tasks or task elements occurred? Was the pace slow and leisurely or rapid and frantic?
Performance	Perfect/failure	How successful do you think you were in accomplishing the goals of the task set by the experimenter (or yourself)? How satisfied were you with your performance in accomplishing these goals?
Effort	Low/high	How hard did you have to work (mentally and physically) to accomplish your level of performance?
Frustration level	Low/high	How insecure, discouraged, irritated, stressed, and annoyed versus secure, gratified, content, relaxed, and complacent did you feel during the task?
ASR-output evaluation scales
Text support	Support/hindrance	Did you obtain benefit from the text or did the text hinder speech comprehension?
Problems errors	Not problematic/severely problematic	To what extent were the ASR errors problematic for text comprehension?
Problems delay	Not problematic/severely problematic	To what extent was the text delay problematic for text comprehension?

NOTE: ASR = automatic speech recognition.