Introduzione in Italiano
InStat
È un semplice pacchetto di statistica che permette di utilizzare procedure statistiche
con semplicità e velocità. A differenza di software molto più potenti
(e costosi) InStat è lo strumento ideale per coloro che, non specializzati nella statistica,
devono analizzare piccoli set di dati.
InStat
is available for both Windows and Mac!
InStat
helps scientists and students conquer routine statistical
procedures with speed and ease. Unlike larger (and much
more expensive) packages, InStat is designed for scientists
and students analyzing small amounts of data. InStat takes
just minutes to master, and can be a perfect companion to
complex programs. Here is what makes InStat stand out from
other statistics programs:
InStat
guides you step by step
InStat conquers the learning curve by escorting you through statistical
analyses one step at a time. You'll master the program in minutes  really.
Clear
choices with explanations
Don't know the name of the test you need? InStat helps you choose a test
by asking you questions about your data. If you are unsure, consult the extensive
help screens, which explain the statistical reasoning in plain language.
Easy
to understand results
InStat doesn't assume that you are a statistics whiz. It presents results
in simple paragraphs, with a minimum of statistical jargon. InStat's help screens
review the use of each test and explain every portion of the results.
Unique
analysis checklists
With other statistics software, it is too easy to get the right answer
to the wrong question. That is why InStat provides unique analysis checklists
to assure that your data have not violated any assumptions of the test, and that
you have chosen a test that matches your experimental design  and really answers
the question you had in mind.
Features
Most statistics programs
are designed by statisticians, for statisticians. These programs are featurepacked
and powerful, but can overwhelm scientists with thick manuals, obscure statistical
jargon and high prices. GraphPad InStatSŽS is different. Designed by a scientist
for scientists.
"InStat takes a kinder,
gentler approach...All prompts to the user are in plain English and simple to
follow. The program guides the user through a fourstep process; defining the
data type, entering data, choosing a statistical test, and presenting the results...The
user navigates easily through these steps, to lucid and complete output...The
analysis checklists are a masterstroke...This small, but effective package is
highly recommended."
John Wass, Statistics, Fast and Easy, Science 282:1652, Nov 27, 1988.
InStat guides you
step by step
InStat conquers the learning curve by escorting
you through statistical analyses. You'll master the program in just a few minutes
 really.
Clear analysis choices
with explanations
You don't have to know the name of the
test you need. InStat helps you pick an appropriate test by asking questions about
your data. If you are unsure, consult the extensive help screens, which explain
the statistical reasoning in plain language.
Easy to understand
results
InStat does not assume that you are a statistics
whiz. It presents results in simple paragraphs, with a minimum of statistical
jargon. InStat's help screens review the use of each test and explain every portion
of the results.
Unique analysis
checklists
With other statistics software, it is too
easy to get the right answer to the wrong question. That's why InStat provides
a unique analysis checklist. Doublecheck that your data have not violated any
assumptions of the test, and that you have picked a test that matches your experimental
design and really answers the question you had in mind.
 Group
comparisons
Unpaired t test
or the nonparametric MannWhitney test.
 Welch's unpaired t test
(does not assume equal standard deviations)
 Paired t test or the nonparametric
Wilcoxon matched pairs test.
 Ordinary oneway ANOVA or
the nonparametric KruskalWallis test.
 Repeated measures oneway
ANOVA (identical to twoway ANOVA without replication)
or the nonparametric Friedman test.
 Follow ANOVA with the Bonferroni,
Tukey, StudentNewmanKeuls or Dunnett multiple comparison
post test, or with the post test for linear trend.
 Follow nonparametric ANOVA
with Dunn's post test.
 One sample t test or the
nonparametric Wilcoxon rank sum test.
 F test or Bartlett's test
to test for equality of standard deviations.
 Perform unpaired t tests
and ordinary ANOVA from either raw data or mean, N and
SD (or SEM).
 Allows missing values in
ordinary ANOVA and unpaired t tests.
 Calculate mean, SD, SEM,
minimum, Maximum and median of each group, and the 95%
confidence interval of the group mean.
 KolmogorovSmirnov normality
test.
 View bar graph of group
means and SD or SEM.

 Contingency
tables
Chisquare test
with or without Yates' continuity correction.
 Chisquare test for linear
trend.
 Fisher's exact test.
 Calculate 95% confidence
intervals for the relative risk, odds ratio or difference
between two proportions.
 Calculate the sensitivity,
specificity,positive predictive value, negative predictive
value and likelihood ratio of a diagnostic test, with
95% confidence intervals.

 Linear
regression and correlation
 Calculate slope and intercept
with 95% confidence intervals.
 Force the regression line
through a specified point.
 Determine new points along
the standard curve.
 Calculate correlation coefficient
(Spearman or Pearson) and its confidence interval.
 Test for departure from
linearity with a runs test or the F test for linearity.
 View scatter plot with regression
line and its 95% confidence interval.

 Multiple
regression and correlation
Calculate a correlation
matrix.
 Multiple regression using
selected X variables.
 For each X variable, compute
its bestfit coefficient with standard error and 95% confidence
interval, and a P value testing whether the variable contributes
significantly to the model.
 Compute the Variable Inflation
Factor (VIF) to test for multicollinearity (whether the
variable is redundant).

 Program
features
 Enter up to 1000 (Windows)
rows and 26 columns of data.
 Mathematically transform
selected data (i.e., logarithm, reciprocal, logit, etc.).
 Transpose Paste. Transpose
rows and columns.
 Copy results or data to
the Macintosh or Windows clipboard, or export as a text
file.
 Print graphs on any printer
or export as Windows Metafile (.WMF) or PICT (Mac) files.
 Annotate your data and analyses
using a builtin notes editor. Notes are included in the
data files.
 InStat files contain analysis
choices as well as data so you can quickly rerun the same
test with multiple sets of data.
 Combine two columns (add,
subtract, multiply, divide) to create a new column.
 Import data from comma or
tab delimited test files.
 Import indexed (stacked)
data, entire tables or selected rows and columns, filter
selected data.
 Export the data table as
a text table, or as indexed (stacked) file.
 Exclude selected values.
They appear on the data table, but are treated as missing
values by the analyses.

 What InStat
does not do
InStat is not for
everyone. It performs basic tests easily, but does not
handle advanced statistical tests. For example, InStat
does not perform twoway (or higher) ANOVA, logistic regression,
the MantelHaenszel test (to analyze a stack of contingency
tables), stepwise multiple regression, analyses of survival
curves, analysis of covariance, factor or cluster analysis,
polynomial regression or nonlinear regression. InStat
is an ideal tool for analyzing experimental data and data
from small clinical studies, but is not designed to analyze
large clinical studies. InStat has limited ability to
select a subset of cases from a large file and cannot
crosstabulate data to form a contingency table.
 System
requirements
 486 or better, Windows 3.1 or
Windows 95/98 (or NT 4.x), 4MB RAM, 3MB free on hard disk
 Mac OS 8.6 through OSX
