Somers' D and Kendall's tau-a are parameters behind rank or nonparametric statistics, interpreted as differences between proportions. Given two bivariate data pairs (X1, Y1) and (X2, Y2), Kendall’s tau-a parameter tau-XY is the difference between the probability that the two X–Y pairs are...

Most Stata users make their living producing results in a form accessible to end users. Most of these end users cannot immediately understand Stata logs. However, they can understand tables (in paper, PDF, HTML, spreadsheet, or word processor documents) and plots (produced by using Stata or...

A resultsset is a Stata dataset created as output by a Stata program. It can be used as input to other Stata programs, which may in turn output the results as publication-ready plots or tables. Programs that create resultssets include xcontract, xcollapse, parmest, parmby and descsave. Stata...

Scientists often have good reasons for wanting to calculate multiple confidence intervals and/or p-values, especially when scanning a genome. However, if we do this, then the probability of not observing at least one "significant" difference tends to fall, even if all null hypotheses are true. A...

An algorithm is presented for calculating concordance-discordance totals in a time of order N log N , where N is the number of observations, using a balanced binary search tree. These totals can be used to calculate jackknife estimates and confidence limits in the same time order for a very wide...

The new book Hardin and Hilbe (Stata Press, 2001) is reviewed. Copyright 2001 by Stata Corporation.

Statisticians make their living producing confidence intervals and pvalues. However, those in the Stata log are not ready for delivery to the end user, who usually wants to see statistical output either as a plot or as a table. This article describes a suite of programs used to convert Stata...

The powercal command can compute any one of the five quantities involved in power calculations from the other four. These quantities are power, significance level, detectable difference, sample number, and the standard deviation (SD) of the influence function, which is equal to the standard...

multproc carries out multiple-test procedures, taking as input a list of p-values and an uncorrected critical p-value, and calculating a corrected overall critical pvalue for rejection of null hypotheses. These procedures define a conÞdence region for a set-valued parameter, namely the set of...