SigmaPlot Version 13 is a scientific data analysis and graphing software package with features that include Forest plots, which combine the results of like studies to improve statistical significance, and Kernel Density — a smooth probability distribution plot — as well as Analysis of Covariance (ANCOVA), which includes the effects of “nuisance” variables, and Principal Components Analysis (PCA) to determine the major data relationships. The software provides researchers with an optimized property interface with no tabs, with all properties displayed in one place and instant graph display upon property change. The Graph Properties panel has an optional transparency to show graph changes behind it. Additional features include dot density graph with mean and standard error bars for improved data description, and Akaike Information Criterion (AICc) in the Regression Wizard and Dynamic Fit Wizard reports and the Report Options dialog.