“…The definitions of each term (frustration, fatigue, motivation, and effectiveness) were provided on the questionnaire to ensure a good understanding of the questions. Likert scales for instant frustration, global frustration, fatigue and motivation were scaled on 7 levels : absent (1), barely perceptible (2), faintly present (3), light (4), marked (5), pronounced (6), strongly pronounced (7). Effectiveness was rated on 5 levels : strongly disagree (1), disagree (2), neither agree or disagree (3), agree (4), strongly agree (5).…”