In the interests of balance, can I just say that I amazed at the amount of time and money spent (I am tempted to say wasted) on tutors.
If your child is suitable for grammar school, they will pass the 11+. If they need extra tutoring to pass the 11+, they are probably better off in a comprehensive.
Am I alone in taking this view ?
We can all trot out anecdote ("my child got in on no tutoring"; "my child was tutored ten hours a day for four years and I know she wouldn't have got in had she had a minute's less") but real research is needed.
I was only able to find a few papers directly on the topic. The first (1) is twenty years old, studies seven children in each arm of the trial and claims huge effects effects from tutoring. Unfortunately, my library doesn't subscribe to the online versions of the BJEP prior to 1999, so I can't read the details from home and therefore I don't know what "tutoring" means: I might wander past the physical library this morning and see if I can find a paper copy, or someone else on the forum might have access to it.
Two 11+ (transfer tests) practice tests, issued by the Department of Education in Northern Ireland, were administered to two groups of primary seven children. One group was intensively coached for the test, while a second group received no coaching. The children in both groups were also assessed on a separate index of ability, Raven's Progressive Matrices. Very large differences were found between the coached and uncoached groups. Differences in the region of 30 to 40+ points were maintained, even when ability as assessed by the Raven's Matrices was held constant. This is in the context of a possible 100-point scale. Differences of this size are some two to three times higher than previously reported estimates. The results also indicate that test scores continued to improve between tests one and two for coached children while remaining stable for the uncoached group, contrary to previous research, which suggested a ceiling effect after a sustained period of coaching.
The second (2) has much larger sample sizes, and is based on intensive in-classroom VR coaching in two schools, with other schools as controls:
This study examines the effects of test familiarisation/practice and coaching on 11-plus test performance. Seven parallel forms of a test were administered to school children (aged 10-11 years) under two conditions. In the first condition children were given 3 hours of coaching prior to the administration of the tests ( n = 311). The second group received coaching only after the third test ( n = 241). Five of the seven tests were administered over a 2-week period and the remaining two were given some 9 months later. (...) The effects of familiarisation/practice did not produce a significant change in the means. Coaching for a period of 3 hours did produce a statistically significant shift in the means, though the individuals maintained their rank order. The effect of sustained coaching over a period of 9 months is shown to be substantial.
I have got the text of this paper, and although I'm slightly surprised they got ethical approval, it looks pretty solid. The statistics are over my head, but the basic contention --- that nine months' intensive coaching in VR improves VR --- doesn't seem unreasonable. What the paper doesn't measure, of course, is the effect all that coaching had on the children in terms of the things they weren't doing.
(2) also cites some other work (3) (4) which seems interesting, especially (4) which is available online without needing a subscription. Psychology isn't my field, and a lot of the language in the later papers needs a gloss, so perhaps someone who understands the field a bit might like to read around and report back. And note that (5) gets referenced a lot, which might be considered something of a warning sign...
(1) The effects of coaching on 11+ scores, Egan, M; Bunting, B. British Journal of Educational Psychology 61. Feb 91 (February 1991): 85-91.
(2) Brendan P. Bunting & Eugene Mooney (2001): The Effects of Practice and Coaching on Test Results for Educational Selection at Eleven Years of Age, Educational Psychology, 21:3, 243-253
(3) Vernon, P.E. (1954). Symposium on the effects of coaching and practice in intelligence tests. British
Journal of Educational Psychology, 24, 57–63.
(4) Allalouf, A., & Ben-Shakhar, G. (1998). The effect of coaching on the predictive validity of scholastic
aptitude tests. Journal of Educational Measurement, 35, 31–47. Text available free: http://www.openu.ac.il/Personal_sites/G ... BJEM98.pdf
(5) Burt, C. (1947). Symposium on the selection of pupils for different types of secondary schools. British Journal of Educational Psychology, 17, 57-71.