“…For this particular body of literature, fatigue and learning (IV-9), and accommodation and washout (IV-10) were applicable for only two studies [
56,
57] . For three articles [
48,
56,
57] classified as before-and-after trials (E5), criteria regarding group comparisons were not applicable (IV-2, IV-3, IV-4 and IV-12). Therefore, overall scores for internal/external validity were assessed using the following criteria:
If more than half of the applicable internal/external validity variables were not addressed or poorly addressed (i.e., marked “no” or “unknown”), then the overall assessment was deemed to be low.
If more than one but less than half of the applicable internal/external validity variables were appropriately addressed (i.e., marked “yes”), then overall assessment was deemed to be moderate.
If one or none of the applicable internal/external validity variables were not addressed or poorly addressed (i.e., marked “no” or “unknown”), then the overall assessment was deemed to be high.
…”