Construct Validity of an Instrument for Assessment of Reflective Writing-Based Portfolios of Medical Students

Figures & data

Table 1 Generalizability Theory Study (G-Study) Results for the Scores of Medical Students (n=129) in Reflective Portfolios Using Two Raters and Three Measurement Occasions

Facets	df	SS	MS	Variance Component	Percent Variance
Students (s)	128.00	501.24	3.92	0.49	46.60%
Raters (r)	1.00	4. 17	4.17	0.01	0.80%
Occasions (t)	2.00	11.27	5.63	0.02	1.90%
s× r	128.00	109.25	0.85	0.19	17.70%
s× t	256.00	102.99	0.40	0.06	5.20%
r× t	2.00	0.44	0.22	0.00	0.00%
s× r x t	256.00	74.96	0.29	0.29	27.70%
Φ = 0.75
Absolute SEM: 0.41

Note: The proportion of observed variance explained by each facet is calculated by dividing the individual variance component by the total observed variance.

Abbreviations: SS, sum of squares; MS, mean of squares; df, degree of freedom; SEM, standard error of measurement.

Figure 1 Decision study (D-study) for the medical students (n=129) scores in reflective portfolio. The dependability coefficients are the estimated Φ-coefficients of combining different numbers of raters and occasions.