| Reference | Country
| Samples | Tests
| Results |
| American College Testing Programme (ACTP 1997-2001)*
| US, nation-wide | 17,765 hs-children, ca. 18 years old; break-down below by school year; 1997 (n=1,926); 1998 (n=4,593); 2001(n=5,379)—and compared with national norm groups of ca. one million per school year.
| American College Test (total score based on four subtests covering the core of the high-school curriculum: English, Mathematics, Reading, Science Reasoning.)
| Hs-children scored higher than the control group by an average 12 (in 1997) to 15 (in 2000) percentile points.
|
| Clavery et al. 1992 | US, Arkansas
| 42.8 he-children, distributed across three age groups (average mean: 10, 13 and 16 years, respectively) and compared with a total of 90,000 same-age peers in the same state who were being educated entirely in school.
| Metropolitan Achievement Test (total score based on five sub-tests: Reading, Mathematics, Language, Science, Social Studies).
| Hs-children scored higher than the control group by an average nine to 13 percentile points.
|
| Galloway 1995 | US, South-eastern states
| 60 hs-children ca. 18 years old ("freshmen" or first-year students at a Christian University) and compared with 120 fellow students who had been educated entirely in school.
| American College Test (see above); essay writing included
| Hs-children scored higher than the control group by an average 13 (essay writing) to 28 (ACT total) percentile points.
|
| Ray 1994 | Canada, nation-wide
| 524 hs-children aged six to 18 (mostly primary school students) and compared with national norm groups.
| Various standardised scholastic achievement tests (including Canadian Test of Basic Skills) covering basic subjects in school curricula.
| Hs-children scored higher across all the tests than the control group by an average 32 percentile points.
|
| Ray 1997 | US, nation-wide |
1,952 hs-children aged six to 18 (mostly primary school students) and compared with national norm groups.
| Various standardised scholastic achievement tests (including the Iowa Test of Basic Skills) covering basic subjects in school curricula.
| Hs-children scored higher across all the tests than the control group by an average 37 percentile points.
|
| Rudner 1999 | US, nation-wide
| 20,760 hs-children aged six to 17 (66 to 2,876 children per yearly age cohort), throughout the entire country and compared with national norm groups.
| Iowa Test of Basic Skills (Administered from age 15 on: Tests of Achievement and Proficiency). In both tests, the total score was based on subtests: Reading, Language, Mathematics, Social Studies, Science.
| Hs-children scored higher than the control group by an average 26 (10-year-olds) to 41 (seven-year-olds) percentile points.
|
| Sutton and Oliveira 1995 | US, SE states
| 58 hs-children, ca. 18 years old (first-year students or "freshmen" at a Christian University) and compared with 789 fellow students who had been educated entirely in school.
| California Critical Skills Test (total score based on five subtests: Analysis, Evaluation, Inference, Deductive Reasoning, Inductive Reasoning.
| Hs-children scored higher than the control group by an average 11 percentile points.
|
| Tipton 1990 | US, Virginia |
62 hs-children, distributed across two age groups 39 nine-year-olds, 23 12-year-olds) and compared with an approximate total of 48,000 same-age peers in the same state who were being educated entirely in school.
| Comprehensive Test of Basic Skills (total score based on five subtests: Language, Reading, Mathematics, Science and Social Studies).
| Hs-children (in both age groups) scored higher than the control group by 1 percentile point on average.
|
1 This table is taken directly from Block 2004: 44-45.
* Internet data source for ACTP: www.act.org.
|
