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100 and 50 years ago
| Content Provider | Semantic Scholar |
|---|---|
| Author | Weil, Anne |
| Copyright Year | 2005 |
| Abstract | 116 NATURE | VOL 433 | 13 JANUARY 2005 | www.nature.com/nature 100 YEARS AGO “Average Number of Kinsfolk in Each Degree.” May I ask you to insert yet another brief communication on the above subject, because private correspondence shows that paradoxical opinions are not yet wholly dispelled? The clearest way of expressing statistical problems is the familiar method of black and white balls, which I will now adopt. Plunge both hands into a dark bag partly filled with black and white balls, equal in number, and well mixed. Grasp a handful in the right hand, to represent a family of boys and girls. Out of this unseen handful extract one ball, still unseen, with the left hand. There will be on the average of many similar experiments, as many white as black balls, both in the original and in the residual handful, because the extracted ball will be as often white as black. Using my previous notation, let the number of balls in the original handful be 2d. Consequently, the number in the residual handful will be 2d 1, and the average number in it either of white or of black balls will be half as many, or d 1 2 . It makes no difference to the average result whether the hitherto unseen ball in the left hand proves to be white or black. In other words, it makes no difference in the estimate of the average number of sisters or of brothers whether the individual from whom they are reckoned be a boy or a girl; it is in both cases d 1 2 . The reckoning may proceed from one member of each family taken at random, or from all its members taken in turn. Francis Galton From Nature 12 January 1905. |
| Starting Page | 116 |
| Ending Page | 116 |
| Page Count | 1 |
| File Format | PDF HTM / HTML |
| DOI | 10.1038/433116a |
| Volume Number | 433 |
| Alternate Webpage(s) | http://www.blc.arizona.edu/courses/schaffer/182/NatureDownloads/LargeMesMamm-NaRev.pdf |
| Alternate Webpage(s) | https://doi.org/10.1038/433116a |
| Journal | Nature |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
