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ordvar-- Ordinal variation and consensus statistics

Syntax

ordvarvarname[if] [in] [,low(#)high(#)]----------------------------------------------------------------------------- The

byprefix is allowed.

Description

ordvarcalculates measures of ordinal consensus and dispersion. These includelsqand 1-lsq, which are 0/1 normed ordinal consensus and dispersion statistics described in Blair and Lacy (2000). The latter statistic is essentially identical to the IOV measure of Berry and Mielke (1992). The non-normed version of the dispersion statistic, termed d-squared by Lacy (2006), is also calculated, as are delta-method standard errors for these statistics. These measures do not rely on assumptions about intercategory distances or distributional form.

Arguments and Optionsvarnameis the variable for which the dispersion and consensus statistics are desired. This variable is assumed to be coded with consecutive integers, starting with the lowest value occurring in the data up to the highest. As an option, to allow for situations in which the lowest or highest theoretically possible value does not occur in the data, the user may specify these values by using the low(#) and high(#) options. Failure to specify this option when necessary will give incorrect results.

Returned results

ordvarsaves the following inr():Scalars

r(onemlsq)1-lsqnormed ordinal dispersion statisticr(lsq)lsqnormed ordinal dispersion statisticr(dsq)d-squarednon-normed ordinal dispersion statisticr(dsqse)standard error ofd-squaredr(lsqse)standard error of 1-lsqorlsq

Examples

. sysuse auto. ordvar rep78.// What if some theoretical minimum or maximum value did not occur in the data?. keep if foreign==1. tab1 rep78. ordvar rep78, low(1) high(5)

ReferencesBlair, J. and M. Lacy. 2000. "Statistics of Ordinal Variation." Sociological Methods and Research. 28: 251-280.

Lacy, M. 2006. "An Explained Variation Measure for Ordinal Response Models with Comparisons to Other Ordinal R2 Measures." Sociological Methods and Research 34:469-520.

Berry, K. J. and P. W. Mielke, Jr. 1992. "Assessment of Variation in Ordinal Data." Perceptual and Motor Skills 74:63-66.

AuthorMichael G. Lacy Colorado State University Fort Collins, Colorado Michael.Lacy@colostate.edu