InStat features list

Column statistics

• Mean, median, 95% CI, SD, SEM. Also tests whether the distribution conforms to a Gaussian distribution using the Kolmogorov-Smirnov test.

Group comparisons

• Paired and unpaired t tests; Mann-Whitney and Wilcoxon nonparametric tests.
• Ordinary and repeated measures ANOVA followed by Bonferroni, Tukey, Student-Neuman-Keuls or Dunnett post tests.
• Kruskal-Wallis or Friedman nonparametric tests followed by Dunn post test.

Contingency tables

• Chi-square test with or without Yates’ continuity correction.
• Chi-square 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 with 95% confidence intervals.

Linear regression and correlation

• Calculate slope and intercept with 95% confidence intervals.
• Force the regression line through a specified point.
• Interpolate from a 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.

Multiple regression and correlation

• Calculate a correlation matrix.
• Multiple regression using selected X variables.
• For each X variable, compute its best-fit 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.

Program features

• Program features
• Up to 1000 rows and 26 columns of data.
• Mathematically transform selected data (i.e., log, reciprocal, logit, etc.).
• Transpose rows and columns.
• Copy results or data to the 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 built-in notes editor.
• InStat files contain analysis choices as well as data so you can quickly rerun the same test with new data.
• Combine 2 columns (add, subtract, multiply, divide) to create a new column.
• Import comma or tab delimited 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.

System requirements

• Windows version – 486 or better, Windows 3.1 or higher, 4Mb RAM, 3Mb free hard disk space.
• Macintosh version – OS 8.6 or higher and 4Mb free hard disk space. InStat 3.0 Mac is a native OS X (carbon) application.

Cross platform compatible

InStat 3.0 is available both for Macintosh and Windows. The two versions are very similar. You can open files created on one platform on the other platform with no special conversion. The program has almost identical interfaces on the two platforms, so you can switch back and forth with virtually no learning curve.

Graphing capabilities

InStat makes notebook quality graphs (not editable). For publication quality graphs, use GraphPad Prism.

What InStat does not do

We designed InStat to simply perform and teach basic statistical tests. Many labs find that InStat is all they need. Other labs sometimes require more advanced statistical tests, or the ability to select subsets of data from large databases. These labs will need a heavy-duty statistical package in addition to InStat. InStat does not perform two-way ANOVA or survival analysis, but Prism, our graphing and curve fitting program, does. InStat also does not perform logistic regression, stepwise multiple regression, factor or cluster analysis, or ANCOVA.