SigmaStat 3.0
by Felix Grant
SPSS has a long and honorable
history in the world of statistics but does not have a reputation
for offering no-brainer solutions to the statistically terrified.
Through numerous acquisitions, the company gradually acquired
several user-friendly packages, but these always sat awkwardly
with its high-end core business. That conflict recently
came to an end when the entity formerly known as SPSS Science
moved to Systat Software International--with the Sigma product
line being the advance party.
If you’re one of the many quality professionals
who smile bravely and pop aspirin like candy when statistics
are required, then SigmaStat is right up your alley. Few
other packages offer a smoother entry, shorter learning
curve and less pain for the reluctant statistician.
To start, there’s the contextual prompter. For example,
if you’ve attempted a t test on unsuitable data that
fails the normality test, most stats packages will give
you a meaningless answer or an error report. Not SigmaStat--it
mentions the problem, then immediately asks if you would
like to run a Mann-Whitney rank sum test instead. Once you’ve
agreed, you get a Mann-Whitney result, helpful background
information and a plain-English explanation of what it means,
all presented in a neat, clear, rich-text report ready for
printing on a half-sheet of paper. Better still, there is
another equally helpful half-sheet explaining why that t-test
wasn’t a good idea, so you can confidently explain
your change of plan to colleagues.
What could be better? Well, the entire package is this
good.
You won’t, for instance, have reached that attempt
on a t test unaided. The “Statistics” menu,
instead of the usual maze of statspeak, is organized along
task-oriented lines. Tests are organized by tasks you might
want to perform. Pick from headings like “Describe
Data,” “Compare Two Groups” or “Before
and After.” This doesn’t suggest that you’ll
never have to do anything; eventually you’ll have
to come against the nitty-gritty. But at least you’ll
arrive at the task through sensible guidance, with helpful
advice at your side and an appropriately selected toolkit
on hand.
That toolkit contains everything you’re likely to
need for day-to-day use in a real-life working quality environment,
from basic descriptives through tests, curve fitting, and
a good survival analysis implementation, all of which are
fast and sleek. Transforms--like Excel formulae, but dedicated
to the needs of statistical work and applied automatically
to a column without any need to copy and paste--are fast,
effective and easy-to-use. Transforming installation and
failure dates into a full component survival analysis report
takes approximately eight mouse clicks.
The reports are page-formatted in U.S. letter shape by
default, but you can change that at will. Users on the metric
system can choose millimeters instead of centimeters or
the default, inches. Page formatting doesn’t have
to include paper: PDF and HTML are available. There are
also ruler bars at the top, plus common word processor functions
such as decimal-aligned tabs, search and replace, go-to,
and date and time fields. And for more advanced report preparation,
moving the results into a word processor or DTP is a snap.
Working with other programs is provided for. SigmaStat
opens a useful range of other file formats directly, imports
from still more (including Microsoft Access) and exports
to a spread of generic ones. Graphs, like statistical methods,
are handled much better by SigmaStat than by Excel. Simple
point-and-clicks result in selective subranges, comparative
multiple plots, true histograms and much more.
The program has its own dedicated native statistical data
worksheet. Although many users might prefer to stick with
Excel (You can, of course, import your Excel data), you
should consider the methodological advantages of using SigmaStat’s
own sheet--well-designed, statistically aware and, at 32
million rows by 32,000 columns, offering much greater process
capacity.
All in all, it’s an ideal package for the day-to-day
needs of a busy professional for whom stats are a necessary
tool, not a major area of expertise. Author and academic
Derek Rowntree famously said that he couldn’t offer
statistics without effort, but he could offer statistics
without tears. SigmaStat can make the same promise.
Felix Grant is a lecturer and research consultant
in the United Kingdom.
SigmaStat
Requirements: Windows 98, 2000, NT 4.0
or XP; Pentium 200 MHz or higher
Price: $599. Government and academic pricing
available
Contact:
- Systat Software Inc.
- 501 Canal Blvd., Ste. C
- Point Richmond, CA 94804
- Phone: (800) 797-7401
- Fax: (510) 231-4789
- E-mail: sales@systat.com
- www.systat.com
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