The Multiple Regressions Chapter is found in modeling documents. The chapter manages entity lists, compilation code, regression values, and regression results. The chapter also provides commands for regressing values into a multiple linear model.

• Regressing a chemicals vapor pressure data into a set of parameters for use in an estimation techniques capable of estimated the property at various temperatures. (See video.)
• Regressing a mixture's activity coefficient data into a set of binary interaction parameters for use by the Margules estimation model. (See video.)
• Regress physical property data from a set of chemicals into a new group contribution technique capable of estimating values for many similarly structured chemicals. (See video.)

The chapter's datapane is divided into eight sections:

Section	Description
Source Knowledge Base Section	used to record the knowledge base that will be used as the source of all entities, physical property data, and estimation techniques as well as the destination of newly regressed variable values.
Regression Specification Section	enables you to specify the entity type, the entities, and the compilation function used to collect values to be used in the regression.
Regression Values Section	displays values for the the compiled x, y, and z regression variable values. Provides you with analysis tools for identifying duplicate rows, correlated variables, values with minimal variation.
Regression Variables Section	displays the optimal values of the regression variables. Variable values as well as their standard errors and confidence intervals are displayed.
Regression Results Section	displays the regression's summary statistics, parity plots, histograms, and residuals. You can use these values to determine the quality of the regression as well as identify ways in which to improve the regression.
Technique Variables Transfer Section	enables you to specify the destination of the regression variable values. Typically, variable values are transferred to one or more estimation techniques within the source knowledge base.
General Notes Section	used to store any general notes about the current regression. Typically, this section is used to detail the criteria used to select regression values and details about the technique transfer specifications.
Associated Documents Section	used to store links to any documents associated with the current regression.

The Multiple Regressions chapter has commands for compiling regression values, regressing these values into a linear model, transferring these regressed variable values to source estimation techniques, and reporting these results. These commands are available from the chapter's Commands menu.

• Open Source Knowledge Base: opens the knowledge base whose name is stored in the Source Knowledge Base Section.
• Report Regression Properties: activates the Report Properties Dialog that enables you to select regression properties and attributes to add to an open Report Document. (Also see documentation on Reporting Properties.
• Compile Regression Values: activates the Regression Values Compilation Dialog: which compiles regression values by executing the compilation code on each entity.
• Clear Regression Results: removes all regressed coefficients, statistics, graphs, and residuals from the current regression. Clearing a regression is typically necessary before input values can be changed.
• Regress Variable Values: activates the Multiple Regression Dialog which enables you to regress coefficients and calculate statistics from the entered regression values.
• Update Regression: reruns the regression using any new or modified values retrieved from the source knowledge base and then displays the updated results in the Updated Multiple Regression Results Dialog.
• Standard Equations: activates the Standard Equations Dialog which displays the named equations known to the application. Viewing these equations before constructing a new regression can be provide helpful.
• Transfer Values: activates the Technique Variables Transfer Dialog which enables you to copy regressed parameters, bips, and group contributions into one or more estimated techniques in the source knowledge base.

The menubar provides numerous other commands for navigation, bookmarking, file operations, units conversion, etc. See the documentation on Common Commands for details.

Topic	Description
Getting Started using Synapse	provides a quick tour of Synapse's capabilities including examples of chemical product design.
Getting Started using Cranium	provides a quick tour of Cranium's capabilities including a discussion of structure editing.
Estimating Chemical Properties	a short video demonstrating how to estimate the physical properties of chemicals using either Synapse or Cranium.
Estimating Mixture Properties	a short video demonstrating how to estimate the physical properties of mixtures using either Synapse or Cranium.