Table 2.

Study 1: Linear mixed model

Contrast	Time	Estimate	SE	df	Lower CL	Upper CL	T ratio	P value
Booklet—control	T1	0.080	0.674	239.421	−1.664	1.825	0.119	0.999
Tutoring—control	T1	0.687	0.730	254.426	−1.202	2.576	0.941	0.783
Tutoring—booklet	T1	0.607	0.712	258.937	−1.234	2.448	0.852	0.829
Tutoring with booklet—control	T1	1.220	0.754	238.114	−0.730	3.171	1.619	0.370
Tutoring with booklet—booklet	T1	1.140	0.751	240.593	−0.803	3.083	1.518	0.428
Tutoring with booklet—tutoring	T1	0.533	0.799	250.776	−1.533	2.600	0.667	0.909
Booklet—control	T2	1.370	0.718	269.655	−0.487	3.226	1.907	0.227
Tutoring—control	T2	0.969	0.753	267.149	−0.977	2.915	1.287	0.572
Tutoring—booklet	T2	−0.401	0.689	241.569	−2.184	1.382	−0.582	0.938
Tutoring with booklet—control	T2	2.199	0.788	259.706	0.160	4.238	2.789	0.029
Tutoring with booklet—booklet	T2	0.829	0.748	238.415	−1.106	2.764	1.108	0.685
Tutoring with booklet—tutoring	T2	1.230	0.780	237.897	−0.789	3.249	1.576	0.394
Booklet—control	T3	0.669	0.753	291.335	−1.277	2.614	0.888	0.811
Tutoring—control	T3	0.855	0.783	285.602	−1.170	2.879	1.091	0.695
Tutoring—booklet	T3	0.186	0.710	258.754	−1.651	2.023	0.262	0.994
Tutoring with booklet—control	T3	2.526	0.900	313.917	0.201	4.851	2.806	0.027
Tutoring with booklet—booklet	T3	1.857	0.847	298.093	−0.330	4.045	2.194	0.127
Tutoring with booklet—tutoring	T3	1.672	0.879	295.129	−0.598	3.942	1.903	0.229

Comparisons between groups (expected values). df = degrees of freedom; SE = standard error. Significant differences (P value < 0.05, in bold) were found only between groups C and TB, and in timesT2 and T3. Estimates indicate the number of correct responses to which those differences are equivalent (e.g., in T3, TB group has 2.526 more correct responses than C group).