Objective and Subjective Evaluation of Online Error Correction during P300-Based Spelling

Table 3

Questionnaire and averaged ratings over the whole group (N = 16). Ratings ranged between 1 (most negative response) and 10 (most positive response).

Questions	Averaged ratings ± SD
Q1. How well did you control the machine?	5.8 ± 1.9
Q2. Did the machine perform well?	6.6 ± 1.8
Q3. Was the task difficult?	4.6 ± 2.5
Q4. Was the task tiring?	5.9 ± 2.3
Q5. Was the task motivating?	7.9 ± 1.4
Q6. Could you predict errors?	4.9 ± 3.1
Q7. How much did errors upset you?	7.3 ± 2.2
Q8. Was the automatic error correction useful?	5.0 ± 2.8