-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 - - 15 - As a final example, then, consider some calculations that were done in 1983 of the percentage of women in the Fellowship in the United States and Canada. The problem was to establish conditions under which any member in that population was equally likely to be chosen for determination of their sex. The approximate solution was to establish conditions under which each group listed at G.S.O. was equally likely to be selected for survey. in 1983 somewhat less than 2% of the groups listed at G.S.O. were selected by a process in which each group in the population was (approximately!) equally likely to turn up in the two percent. On the average, about 20 members per group are expected to be reached in that way, and in 1983 we had responses from about 7,000 individuals. A biased result would have been obtained if all these individuals had been selected from one state, or one region, or by a number of people around the country selecting the groups they thought were the best groups, or the groups they thought were most typical, etc. In the random sample actually used, the percentage of women in 1983 was determined to be 31 percent. Because we did not determine the sex of every member of the Fellowship, this result can only have approximate validity when applied to the population. However, statistics allows precise statements to be made about the extent of its validity, in terms of probabilities. Confidence Limits: If we have succeeded in establishing random conditions, then mathematical statistics can give a table of the relationship between (1) the probability that the percentage of women in the entire population falls within certain limits around the percentage in the sample, and (2) the width of those limits; for example: Statement of Confidence in the result the statement 31% +- 2% 99% 31% +- 1% 90% 31% +- 0.5% 75% The meaning of the entries in the table is this: If I want to make a statement that is 99% likely to be correct, I can only say that the percentage of women in the population lies between 29 and 33 percent. If, however, I am content to make a statement that is only 90% likely to be correct, then I can say that the percentage of women lies between 30 and 32 percent. Statisticians usually attribute significance only to state- ments made with more than 90% probability of being correct. This table approximates the actual confidence one can have in the statement of the 1983 survey about the percentage of women in the sample, and, when corrected for frequency of attendance at meetings, in the population sampled. However, the term "A.A. member" is very loosely defined and includes many not in the population sampled. Whether such members differ from the sampled population in other respects, and by how much, is not known. -----BEGIN PGP SIGNATURE----- Version: PGP Personal Privacy 6.5.8 iQA/AwUBQk80Qrw9MOKEeRC8EQIq1gCfQcD3/BLcpziZrEqaGg2O9FuG9YkAn3Wf cYSDEJvhEdaq8/zyBWW7vP+2 =7cUm -----END PGP SIGNATURE-----