Doing a Number on Statistics

Mention the word statistics and you are bound to either scare or bore most people. Scare them if they’ve got to produce statistics and bore them if they have to read statistics.

The folks at SPSS Inc. in Chicago--(800) 543-2185--have done a lot to overcome both problems with SPSS for Windows, $395 introductory price until Sept. 30, $695 thereafter.

Statistics software isn’t just for academia, although that’s where it got its start. There are many business problems--personnel policies, comparative sales results and market survey research, to name but a few--that can benefit from statistical analysis.

Several stumbling blocks to statistical analysis are eliminated with SPSS for Windows. You don’t have to be a programmer to use it and you don’t have to be a statistician to understand it.

Data from virtually any source, such as database programs on PCs or mainframes, and popular spreadsheet programs including Lotus 1-2-3 and Microsoft Excel, can be easily utilized by SPSS for Windows.

Although data can be edited in the program’s spreadsheet-like display, this is data analysis software, not data management software. So you’ll want to use it in conjunction with your favorite data management programs, not in place of them.

Computer data systems often use code numbers instead of names to represent things. For instance, you may think of it as the Malibu sales office, but the computer knows it as “491338.” SPSS for Windows allows you to display either the computer codes (values) or the names (labels), which makes it much easier to understand the data.

There are some tasks that statistical software performs effortlessly that are complicated, or even impossible, to do with popular database and spreadsheet software.

Often you want to know how many of something you have; how many of each part you have in your parts inventory, for instance. In statistics, that is called a “frequency” and generating frequency counts of some or all of your data variables is as easy as making a selection from a pull-down menu and then using the computer’s mouse to point to each variable you want counted.

Another common statistical tool is called a “crosstab,” which is shorthand for cross tabulation.

If you want to know how many men and women hold each job category in your company, you would cross-tabulate job category by sex. The leading database and spreadsheet programs today will give you the numbers for such crosstabs.

But SPSS (and other statistical software) also give you the percentages that each number in the crosstab represents, which is usually more important than the number itself.

With just a click of the mouse button to turn on an option, SPSS for Windows will also give you the expected value for each cell in the crosstab matrix. Comparing actual values to expected values (the values if all the jobs were evenly distributed) quickly highlights discrepancies.

Of course, statistics can go far beyond that, actually measuring the degree of discrepancy and finding the most important factors. SPSS for Windows will quickly calculate dozens of summary, comparison, correlation, regression, non-parametric and multiple response tests just by making choices from pull-down menus and following the on-screen guidance in dialogue boxes.

If the statistics provided in the base system are not enough, several add-on modules are available to meet most specialized needs.

The tables produced are usually easily understood, but titles and labels may not be formatted the way you want. Unfortunately the program doesn’t let you do much about that. But you can buy an additional module that will produce presentation-quality tables.

Often the best way to display statistical results is with a graph. SPSS for Windows can produce a variety of bar, line, area, pie, high/low/close and mixed charts for categorical data depiction. It also does histograms and scatter plots, which can graphically analyze data.

All of the charts can be displayed three-dimensionally and any axis can be rotated to achieve maximum clarity. Each element of a chart can be edited on screen so that you can do some customization and annotation.

Finally, you can use SPSS for Windows to prototype programs for mainframe versions of SPSS. The menu and dialogue box choices you make actually produce SPSS program commands that are stored in background in a “journal” that can be saved and transferred to run in the mainframe version. So the Windows version actually allows non-programmers to become mainframe statistics programmers.