By Charles Seiter
Microsoft Excel's tools for exploratory data analysis are meager–a limited assortment of 3-D and pseudo-3-D graph types. The developer of Data Desk, a longtime Mac statistics favorite, has come up with a simple solution to Excel's shortcomings: add commands that allow access to Data Desk from within Excel. Data Description's Vizion 1.0 aims to give business users a quick way to analyze the data residing in piles of accumulated spreadsheets–and somewhat surprisingly, it succeeds.
It's surprising because a program has to be designed very carefully to avoid making data mining more trouble than it's worth. Vizion gives you just three Excel menu items; pick one of these and tell Vizion where to find the data to use, and you instantly pop into an environment that performs most kinds of analysis with simple graphics and easily offers complete hand-holding for all program functions.
To start an analysis, you select some data columns in your Excel spreadsheet, pick the corresponding item from the Vizion menu in the Excel menu bar, and are transported to a Vizion page where you'll find every useful graphical analysis of your data. You don't have to pick and choose among statistical tests, because Vizion chooses the appropriate parts of the Data Desk test repertoire for your data and does all the calculation and graphing for you.
Vizion's speed isn't impressive in the simplest cases–even Excel can draw a modest column plot fairly quickly. But Vizion can turn 500 rows by 3 columns into a 3-D rotating scatterplot in a second, along with boxplots and dotplots (plot types that aren't otherwise available in Excel) of the same data. Data Desk-style palettes let you work directly with Vizion graphics, using simple mouse actions rather than plodding through dialog boxes. Tables provide standard summary statistics for variables and their combinations, and you can get clear explanations of what all those table values and graphs mean by clicking in any screen. And Data Description offers separately optimized versions of Vizion for Power Macs and 680X0 machines, which explains why the add-on is so much faster than Excel itself.
The only possible complaint about Vizion is that it assumes that you have a vision of your own. If you're absolutely clueless about statistical graphics in a business context, you'll find only a few sample files in the tutorial to help you.
Vizion is the first serious attempt to make the tools of exploratory data analysis, rather than classical table-oriented summary statistics, available to Excel users. Using it is the quickest way to find the relationships lurking in the piles of sales, marketing, and financial data in business spreadsheets.
PROS: Simple, efficient tool for data visualization; fast performance on large data sets. CONS: Needs more sample files. COMPANY: Data Description (800/573-5121, http://www.datadesk.com ). LIST PRICE: $150.
August 1999 page: 56
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