Table 4.

Corrected item-subscale and item-total Spearman’s ρ correlation coefficients, by rater

Subscale	Item	Corrected item-subscale correlation, ρ (95 % CI)		Corrected item-total correlation, ρ (95 % CI)
		Rater 1	Rater 2	Rater 1	Rater 2
Engagement	1	.80 (.65–.89)	.81 (.68–.89)	.78 (.61–.88)	.74 (.55–.86)
	2	.82 (.64–.92)	.79 (.64–.89)	.78 (.62–.88)	.75 (.57–.86)
	3	.47 (.20–.68)	.71 (.52–.84)	.35 (.06–.59)	.62 (.37–.78)
	4	.62 (.35–.82)	.44 (.15–.69)	.54 (.24–.76)	.28 (−.03–.56)
	5	.61 (.39–.77)	.54 (.28–.74)	.77 (.60–.88)	.69 (.48–.84)
Functionality	6	.64 (.41–.82)	.62 (.40–.76)	.48 (.20–.69)	.42 (.11–.67)
	7	.50 (.22–.72)	.71 (.51–.84)	.33 (.02–.60)	.62 (.38–.79)
	8	.75 (.56–.88)	.78 (.63–.87)	.45 (.17–.68)	.74 (.57–.86)
	9	.65 (.44–.81)	.80 (.62–.90)	.53 (.29–.70)	.73 (.53–.86)
Aesthetics	10	.69 (.45–.84)	.60 (.36–.78)	.82 (.66–.91)	.69 (.50–.83)
	11	.75 (.55–.89)	.88 (.80–.93)	.60 (.35–.78)	.75 (.57–.86)
	12	.86 (.73–.93)	.87 (.76–.93)	.68 (.48–.82)	.75 (.55–.87)
Informationa	13	.33 (.03–.58)	.43 (.14–.66)	.30 (−.02–.59)	.43 (.11–.69)
	14	.32 (.01–.59)	.34 (.01–.63)	.23 (−.11–.54)	.27 (−.06–.56)
	15	.70 (.51–.84)	.76 (.62–.83)	.61 (.35–.80)	.58 (.36–.76)
	16	.49 (.22–.71)	.51 (.29–.67)	.73 (.54–.86)	.56 (.28–.77)
	17	.54 (.23–.77)	.54 (.28–.71)	.63 (.39–.79)	.71 (.52–.84)
	18	.62 (.42–.76)	.59 (.36–.77)	.61 (.38–.78)	.57 (.33–.76)
Subjective quality	20	.94 (.90–.97)	.89 (.80–.94)	.89 (.79–.94)	.83 (.69–.90)
	21	.88 (.77–.94)	.86 (.75–.92)	.81 (.67–.89)	.81 (.69–.88)
	22	.88 (.81–.92)	.79 (.65–.86)	.81 (.65–.90)	.69 (.51–.80)
	23	.95 (.91–.97)	.94 (.89–.97)	.89 (.79–.94)	.88 (.79–.94)

^aItem 19 was excluded from all calculations because of lack of ratings