The essentials of mental measurement / by William Brown.

  • Brown, William, 1811-
Date:
1911
Catalogue details

Licence: In copyright

Credit: The essentials of mental measurement / by William Brown. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

    52/172 (page 40)
    (1) calculate the moment-coefficients v\, v\, v'.^, v\ about a convenient arbitrary ordinate, (2) transfer to the mean by the equations Vi = v\ - 4i/'i v\ -t- 6j/'i^ v\ - 3i/',* (y'l, or is the distance of the mean from the arbitrary ordinate), (3) determine the corresponding moments for the curve by the equations t^ — v^. — \ fis = V3 I Sheppard's corrections. = f4 - + iTuJ [N.B. For these corrections to be applicable, two conditions must be fulfilled: (i) there must be high contact, (ii) the grouping of the frequencies must be equal.] (4) Calculate /3i and ^2 by the equations These results give the distance of the viean (v\ or d) from the arbitrary ordinate, the standard deviation (V/Xs), and the mode, The investigator may then proceed to determine to which of the seven Pearsonian types the particular curve belongs, to find its equation, and to plot it. For instructions on these points the reader is referred to Palin Elderton's book already mentioned.