Table 5.

Examination of Unit-Level Variation for the ACT Variables

Dependent Variable	Variance	Null	Model11	Model22	Model33
Leadership	Variance component	0.1298**4	0.1205**	0.1036**	0.0797**
	ICC	0.2032	0.2073	0.1835	0.1473
	Explained variance (R2)	N/A	0.0716	0.2018	0.3863
Culture	Variance component	0.0257**	0.0165**	0.0154**	0.0003
	ICC	0.0928	0.0745	0.0697	0.0016
	Explained variance (R2)	N/A	0.3581	0.4021	0.9875
Evaluation	Variance component	0.1169**	0.1156**	0.0964**	0.0258*
	ICC	0.1770	0.1774	0.1524	0.0459
	Explained variance (R2)	N/A	0.0111	0.1754	0.7795
Social Capital	Variance component	0.0171**	0.0147**	0.0158**	0.0018
	ICC	0.0777	0.0716	0.0766	0.0095
	Explained variance (R2)	N/A	0.1437	0.0789	0.8940
OS-Staffing	Variance component	0.2555**	0.2042**	0.2004**	0.1698**
	ICC	0.2395	0.2199	0.2168	0.1900
	Explained variance (R2)	N/A	0.2008	0.2157	0.3354
OS-Space	Variance component	0.2136**	0.2078**	0.2105**	0.1104**
	ICC	0.2634	0.2709	0.2734	0.1648
	Explained variance (R2)	N/A	0.0272	0.0145	0.4831
OS-Time	Variance component	0.0371**	0.0304**	0.0300**	0.0169*
	ICC	0.1168	0.1050	0.1039	0.0615
	Explained variance (R2)	N/A	0.1807	0.1905	0.5430
Formal Interactions	Variance component	0.1730**	0.1375**	0.1145**	0.0963**
	ICC	0.161	0.1386	0.1181	0.1012
	Explained variance (R2)	N/A	0.2052	0.3382	0.4435
Informal Interactions	Variance component	0.2886**	0.2180**	0.2287**	0.0710
	ICC	0.1155	0.0938	0.0979	0.0326
	Explained variance (R2)	N/A	0.2446	0.2076	0.7541
Structural and electronic resources	Variance component	0.3490**	0.2840**	0.3059**	0.1655*
	ICC	0.0979	0.0831	0.0890	0.0502
	Explained variance (R2)	N/A	0.9169	0.9110	0.9498

¹ Model 1: HLM with individual level covariates only

² Model 2: HLM with individual level covariates + specialty

³ Model 3: HLM with both individual + specialty + unit level covariates

⁴ Test whether unit error variance is greater than 0 (*: significant at 0.05 level, **: significant at 0.01 level)