Optimizing Reliability of Digital Inclinometer and Flexicurve Ruler Measures of Spine Curvatures in Postmenopausal Women with Osteoporosis of the Spine: An Illustration of the Use of Generalizability Theory

Table 4

Estimates of variance components^a for Kyphotic index using G-theory and classical test theory.

Variance component	G-theory σ ^2	Classical Test Theory σ ^2
		Rater 1	Rater 2	Trial 1	Trial 2	Trial 3
Patient	25.263	21.227	30.303	23.593	25.733	25.233
Rater	0.488	—	—	—	—	—
Trial	0.083	—	—	—	—	—
Patient * rater	0.563	—	—	—	—	—
Patient * trial	0	—	—	—	—	—
Rater * trial	0.098	—	—	—	—	—
Error	1.023	0.919	1.256	1.901	2.974	1.641

^aestimates having negative values are set to zero.