XVIL.—SIMPLER CASES OF SAMPLING FOR VARIABLES. 355
(17) PearL, RAYMOND, “On certain Points concerning the Probable Error
of the Standard-deviation,” Biometrika, vol, vi., 1908, p. 112. (On
F the amount of divergence, in certain cases, from the standard error
o/~/2n in the case of a normal distribution.)
(18) PEARSON, KARL, and L. N. G. Fox, “On the Probable Errors of
Frequency Constants, and on the Influence of Random Selection on
Variation and Correlation,” Phil. Trans. Roy. Soc., Series A, vol. cxei.,
1898, p. 229,
(19) PEARrsoN, KARL, ‘“On the Criterion that a given System of Deviations
from the Probable in the Case of a Correlated System of Variables is
such that it can be reasonably supposed to have arisen from Random
Sampling,” Phil. Mag., 5th Series, vol. 1., 1900, p. 157.
(20) PrarsoN, KarL, and others (editorial), “On the Probable Errors of
Frequency Constants,” Biometrika, vol. ii., 1903, p. 273, and vol. ix.,
1913, p. 1. (Useful for the general formule given, based on the
general case without respect to the form of the frequency-distribution. )
(21) Pearson, KARL, ““ On the Curves which are most suitable for describing
the Frequency of Random Samples of a Population,” Biometrika, vol.
v., 1906, p. 172.
(22) PEARsoN, KARL, “Note on the Significant or Non-significant Character
of a Sub-sample drawn from a Sample,” Biometrika, vol. v., 1906,
e181,
(23) Pains, KARL, “On the Probability that two Independent Distributions
 of Frequency are really Samples from the same Population,”
Biometrika, vol. viii., 1911, p. 250, and vol. x., 1914, p. 85.
(24) PEARSON, KARL, “On the Probable Error of a Coefficient of Correlation
as found from a Fourfold Table,” Biometrika, vol. ix., 1913, P: 22.
(25) Pearson, KARL, “On the Probable Error of a Coefficient of Mean
Square Contingency,” Biometrika, vol. x., 1915, p. 590.
(26) REIND, A., “Tables for Facilitating the Computation of Probable Errors
of the Chief Constants of Skew Frequency-distributions,” Biometrika,
vol. vii., 1909-10, p. 127 and p. 386.
(27) SuEPPARD, W. F., ““On the Application of the Theory of Error to Cases
of Normal Distribution and Normal Correlation,” Phil. Trans. Roy.
Soc., Series A, vol. excii., 1898, p- 101.
(28) Soper, H. E., “On the Probable Error of the Correlation Coefficient
to a Second Approximation,” Biometrika, vol. ix., 1913, p. 91.
(29) Soper, H. E., “On the Probable Error of the Bi-serial Expression for
the Correlation Coefficient,” Biometrika, vol. X., 1914, p. 384.
(80) “STUDENT,” “On the Probable Error of a Mean,” Biometrika, vol. vi.,
1908, p. 1. (The standard error of the mean in terms of the standard
error of the sample, )
(31) “STUDENT,” “On the Probable Error of a Correlation Coefficient,”
Biometrika, vol. vi., 1908, p. 302. (The problem of the probable error
with small samples, )
(32) “STUDENT,” “On the Distribution of Means of Samples which are not
drawn at Random,” Biometrika, vol. vii., 1909, p. 210.
(33) YuLe, G. U., “On the Theory of Correlation for any number of Variables
 treated by a New System of N otation,” Proc. Roy. Soc., Series
A, vol. Ixxix., 1907, p. 182. (See pp. 192-3 at end.)
(34) YULE, G. U., “On the Methods of Measuring Association between two
Attributes,” Jour. Roy. Stat. Soc., vol. Ixxvi., 1912. (Probable error
of the correlation coefficient for a fourfold table, of association coefficients,
 ete.)
Reference may also be made to the following, which deal for the
most part with the effects of errors other than errors of sampling : —