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StatPlus is based on a Windows program, but it is not by any means a simple port; AnalystSoft reprogrammed it completely in Applescript, optimized for either Intel or PPC (which means it takes advantage of the G4 and G5’s math capabilities). Because of this, it acts just like a Mac program, and has none of the usual quirks of Windows ports; that said, it has its own quirks, as one would expect from, well, software, particularly software that uses Microsoft Excel.
The basic idea is very clever. The weakness of many statistical packages is their spreadsheet-style data view, which is often either lacking completely, or is clunky (SPSS), or extremely clunky (Stata). Many people end up using Excel to prepare their data and perhaps make simple tables, and then go into serious statistical machines to run analyses, and sometimes copy tables out of SPSS or R or Stata and paste them into Excel. Why not just use Excel to hold the data and findings? That’s the StatPlus system: it uses Excel to keep the data, and for that matter, to hold the results.
StatPlus itself is a fairly small, fast-loading program that has a small number of menus — one that launches Excel; one that provides statistical analyses; and one that manipulates data. The analyses menu provides simple, easily understood categories, and underneath those are submenus with the actual operations. It’s easy to learn, yet contains numerous statistical methods that are not normally provided by easy-to-learn software, including one, two, and three way ANOVAs, GLM models, and many other analyses. The Help system is fully developed, in a standard Mac format, and is moderately easy to read.
(Our review doesn’t cover the recent 4.8 update, which adds compatibility fixes, performance, and support of other separators).
You can also prepare your data with tools above and beyond those provided by Excel:
Once you select a procedure, you get a dialogue box asking you to select a range in Excel. If you've already done that, just click Range; you will be put into Excel, but you can just come back to StatPlus. If you haven't already selected the range of data you want, the program will still put you into Excel, where you can select what you want and then return by clicking on StatPlus in the dock or cloverleaf-tabbing back.
It may take a minute, but you will get an intermediate box like the one above (for frequency tables); Advanced options is often grayed out. Once you click on OK, it can take anywhere from the blink of an eye to around ten seconds for a moderately sized data set to get analyzed, with no feedback at all. Then Excel opens up, a new worksheet is created, and the program writes out its tables to Excel.
The reason this layout looks a little funny is that the system only prints out the area underneath the line, which makes large correlations more readable. Unfortunately, it also prints out everything you see above, whether you want it or not; there's no abbreviated version with just the R and an asterisk to show if it’s significant at a particular level. Also, while it shows t and whether the null hypothesis was accepted (presumably at p≤.05), the number of cases is not shown - probably because it can’t be calculated with missing values. (The significance level in the example is pretty random, just as the data was, and so the null hypothesis was accepted.)
Regressions include the R, R-square, adjusted R-square, and the weighting of coefficients with the intercept. A surprising number of regression types are allowed, but options are limited — for best subsets, the minimum probability to enter; for linear, residual and line fit plots can be added. (Best Subsets is also known as stepwise regression; simultaneous regression tests all variables as independent and dependent.)
Of course, there are sometimes quirks, probably because Excel has so many, but some are straight from StatPlus. For example, this is a minor usability issue from a frequency count, where Yes and No were used for no apparent reason (it’s assumed the user knows the difference between discrete and continuous data):
More seriously, we had one dataset that we just could not clean up for use with the program, even if we selected a range of data with no missing values. The error messages were not helpful:
One of the problems appears to be that StatPlus can't deal with empty cells in most analyses, at least as far as we can tell. It should be able to ignore them and, in the case of regressions or correlations, kick out pairwise or listwise comparisons. Instead, it simply grinds to a halt with the message shown above - “No data was returned. Check your input data.”
Chris Swain noted that csv files imported into Excel have to have their name changed to remove the "." or StatPlus fails to identify the input data; saving as an Excel file may fix that, since it does fine with files named something.xls.
When StatPlus does work, it can be impressive, if slow with larger datasets:
The general usage of StatPlus can be a little awkward, with a lot of switching between the program and Excel, and no indication of when the program is working, with delays between selecting a process or a range and getting some sort of reaction.
When all is said and done, StatPlus can be a handy tool for the statistical dabbler who uses Excel to prepare both their data and their output, but its cost rivals that of numerous other programs that keep everything self-contained, and it seems to lack some common sense with regard to data preparation. It’s certainly worth a look if you’re an Excel maven and don't have a lot of missing values in your data.
Also read Chris Swain’s excellent StatPlus:Mac review.
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We are actively soliciting your opinions and reviews of this software - particularly the open source packages!
Originally prepared by Joel West of the UCI Graduate School of Management. Copyright © 1996-2004 Joel West, Copyright © 2005-2008 Allpar, LLC. All rights reserved. Organizational change and organizational development articles | Chevy SSR