The detection of multicollinearity
ndCurveMaster offers multicollinearity detection option through the use of a variance inflation factor (VIF) to improve the quality of models which are developed. The VIF index is commonly used for the detection of multicollinearity (more details can be found here). There is no formal VIF value to determine the presence of multicollinearity. Any VIF values that exceed "5" are often regarded as an indication of multicollinearity, but in weaker model values above "2.5" this may be a cause for concern.
ndCurveMaster calculates the VIF values of each model. These VIF values are shown in the penultimate column of the regression analysis table for each predictor, see below:
Additionally, ndCurveMaster provides a search feature for models based on a specified VIF limit value. Users can select the "VIF cannot exceed" checkbox in the "Settings" window to display only those models that do not exceed the selected VIF value. The default VIF limit value is set to "5", as shown below:
The user can increase or lower the limit.
Detailed explanation on identifying and fixing multicollinearity can be found here.