Table 2.

Performance of teachers and students on the 5–8 field-test forms^a

		Students					Teachers
Test	Items	n	Mean	SD	KR20	Anchor	∆	n	Mean	SD	Core
101	24	885	0.60	0.18	0.76	0.63	0.03	15	0.90	0.08	0.95
102	25	1416	0.62	0.22	0.86	0.58	−0.02	12	0.95	0.04	0.98
103	25	905	0.60	0.22	0.85	0.62	0.01	16	0.94	0.08	0.96
104	25	1178	0.61	0.20	0.82	0.60	0.00	12	0.94	0.04	0.99
105	26	656	0.50	0.19	0.79	0.60	0.00	6	0.91	0.11	0.98
106	23	1222	0.68	0.22	0.85	0.58	−0.02	8	0.92	0.08	0.89
107	25	1470	0.61	0.19	0.81	0.61	0.00	12	0.91	0.07	0.93
108	26	2174	0.62	0.20	0.83	0.58	−0.02	13	0.96	0.06	0.93
109	26	1233	0.60	0.18	0.79	0.64	0.04	14	0.95	0.04	0.97
110	25	1473	0.59	0.19	0.81	0.57	−0.03	14	0.93	0.07	0.97
111	23	1632	0.64	0.22	0.84	0.58	−0.02	13	0.98	0.02	0.98
112	24	1150	0.68	0.20	0.83	0.63	0.02	12	0.95	0.05	0.99
113	25	1622	0.61	0.18	0.79	0.64	0.04	15	0.94	0.04	0.97
114	25	1544	0.64	0.20	0.82	0.59	−0.01	24	0.94	0.06	0.95
115	25	1277	0.58	0.19	0.81	0.61	0.01	8	0.89	0.07	0.95
116	23	1100	0.73	0.21	0.85	0.60	0.00	11	0.98	0.04	0.97
Core	7	20,937	0.60	0.23	0.55	0.60	0.00	205	0.96	0.08	0.96

^aThis table summarizes the 16 field tests involving 20,937 students of 205 teachers. The student mean scores on each test range from 0.50 to 0.73. The measure of internal consistency, KR20, is 0.76 or higher for each test of students. Teachers’ mean scores are much higher than those of students. Subsample performance based on anchor (core) item scores is calculated.