A Review of Current SPSS Products: SPSS 12, SigmaPlot 8.02, SigmaStat 3.0, Part 1

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SPSS has recently released three updates to its major software offerings. SPSS 12 is being released as I write this--September 2003. SigmaPlot is SPSS's mainstay graphics package. Version 8.02 became available to users early in 2003. It ties in with SPSS 12 in a nearly seamless manner, making it appear that it is itself part of the main SPSS package. SigmaStat, which has not seen an update for many years, was presumed by many to be at a dead end. That is, many researchers believed that SPSS, Inc. intended to phase out support, and encourage users to "upgrade" to the main SPSS package. But the package has had a loyal following that has continually persisted encouraging SPSS, Inc. to keep SigmaStat a viable product. They also gave their list of desired enhancements. SPSS, Inc. did not fail their user base.

SigmaStat is intended for use by those who would otherwise tend to limit their statistical usage to SPSS Base, with the addition of basic survival analysis, nonlinear regression, logistic regression, sample size determination, and graphical support for its descriptive and modeling capability. I believe that the primary users are researchers who are not professional degreed statisticians and who use the software for pharmaceutical testing and for biostatistical and social science projects. They are individuals who desire a low-cost package with which to manage, analyze, and report/display relatively small projects. More detailed information on this product, as well as on SPSS and SigmaPlot in general, can be obtained bi-weekly by way of an E-mail newsletter at www.spss.com/newsltrs/spssupdate.

Even a cursory review of these three packages would consume many pages. Hence I intend to divide the review into two parts. In this, the first part, I shall review the capabilities of each of the packages. For those who are already familiar with the software, I shall also spend time describing those features that have been added, or enhanced, to previous releases. At times, in the context of describing areas of enhancement, I may interject various thoughts about the software and mention what I believe to be shortcomings or even omissions that may hinder software usefulness. But for the main, I intend to delay critical comment until Part 2, which is planned for the next issue of The American Statistician.

I should clarify at this point that SPSS has in general listened to user complaints--both with respect to capability additions, as well as enhancements to the software as it has existed. Certain calculations and subsequent results that have been widely criticized by users over various list servers, and in print, have been addressed--at least the ones of which I am aware. Details will be examined in Part 2.

In addition to dividing the review into two parts, Part 1 is also sectioned into topic areas. I shall break discussion into the following areas:

* Overview

* SPSS 12

* SPSS Base and Specialized Modules

* SigmaPlot 8.02

* SigmaStat 3

1. OVERVIEW

For many years SPSS used to be considered as an acronym for "Statistical Package for Social Sciences." This was the name given it in 1968 by its initial developers, Norman Nie, Tex Hull, and Dale Bent. I suspect that now no one, and certainly not the folks at SPSS, Inc., would think of SPSS as a package that is focused on research related to social sciences. Rather, SPSS is widely used in business, health research, survey analysis, data management, education, agriculture, hard sciences, and just about every area in which data management and statistical analysis are important. It has been used by statisticians and researchers for some 35 years now, first in a mainframe setting and then, beginning in 1984, also on PC's under various operating systems. The first SPSS PC system, called SPSS/PC+, ran under MS-DOS; the first Windows implementation was released in 1992. …