An Introduction to the theory of statistics

Bibliographic data

Monograph

Identifikator:: 1751730271

URN:: urn:nbn:de:zbw-retromon-127610

Document type:: Monograph

Author:: Yule, George Udny http://d-nb.info/gnd/12910504X

Title:: An Introduction to the theory of statistics

Edition:: 8. ed. rev

Place of publication:: London

Publisher:: Griffin

Year of publication:: 1927

Scope:: XV, 422 S; Ill., Diagr

Digitisation:: 2021

Collection:: Economics Books

Usage license:: Get license information via the feedback formular.

SUPPLEMENTS—NOTES SUPPLEMENTARY TO CHAPTER VI. 363 Table A shows results for four observers as illustrations, the frequencies being reduced for comparability to a total of 1000. Column A is based on measures by myself, on drawings, to the nearest tenth of a millimetre. It is recognised, of course, that measures cannot really be made to such a degree of precision ; but I believed that I was making them carefully, and as they were made with a Zeiss scale, in which the divisions are ruled on the under side of a piece of plate-glass, readings are unaffected by parallax. Nevertheless it will be seen that I heavily over- emphasised the zeros, and also 2, 8 and 9—an odd selection of preferences! On the whole, the centre of the millimetre was neglected and measures piled up at the two ends. The data for columns B, C, and D were all drawn from the same published report, and refer to sundry head measurements taken on the living snbject. Guided by a statement in the intro- duction, it was possible to compile the data separately for the three assistants (B, C, D) who had done the actual measuring. It will be seen that B was rather good : there is a relatively slight excess at 0 and 5, but otherwise his measurements are fairly uniformly distributed. C was decidedly not good, rounding off nearly one measurement in two to the nearest centimetre or half-centimetre. D was simply outrageously bad—so bad that it might have been better not to publish his measurements. Nearly 57 per cent. of his measurements are made only to the nearest centimetre or half centimetre—a quite inadequate degree of precision for head measurements often only a few centimetres in magnitude. Compilation of data in the form of Table A is recommended as some control of their value, and as a check on assistants. 15. The Extremely Asymmetrical or J-shaped Distribution.— Dr J. C. Willis has shown that any number of illustrations of this form of distribution may be obtained by compiling the frequency distribution for numbers of genera with 1, 2, 3 . . . species in any biological group. Table B shows the distribution for the Chrysomelid beetles. [TaBLE

Access restriction

Copyright

fullscreen: An Introduction to the theory of statistics

Monograph

Table of contents

Download

Monograph

Chapter

This page

Image fragment

Citation links

Citation recommendation