Have an idea?

Visit Sawtooth Software Feedback to share your ideas on how we can improve our products.

Modelling of not-mutually exclusive attributes

Hello,
I've got the same problem described above. my attribute levels are not mutually exclusive.
In the answer is stated that I could include interaction terms. How would I do that.
In my study I examine the importance of different house features and I have among others the attribute security with the levels surveillancy camera, fire alarm, gas alarm, motion detector. these attribues aren't mutually exclusive. How can I solve this using interaction terms? And what is meant with "to collapse binary attributes into a single attribute"?

Thank you very much for helping!
asked Jul 12, 2015 by miri1578 (140 points)

1 Answer

0 votes
Interaction terms are easy to add using our software.  Assuming you are working with CBC within our SSI Web system, you click Analysis + "HB"...then you click the Settings button...then you click Attribute Coding.  At the bottom of the dialog, click the green "plus" icon to add interaction terms to the model.  Pick two attributes from that dialog to interact.

Collapsing two binary attributes into a single attribute is done (with some data processing work on the .CSV file that you can export from SSI Web of the CBC data...it's the format for raw CBC data to take to our standalone CBC/HB system for HB estimation)...as follows:

Assume you had two 2-level attributes.  The number of attribute level combinations between those two is four: 1,1...1,2...2,1...2,2.   So, think about a single 4-level attribute that encodes the information you previously had specified as two 2-level attributes.  The mapping is as following:

Level 1 of the collapsed attribute is coded when the 1,1 combination occurs

Level 2 of the collapsed attribute is coded when the 1,2 combination occurs, etc.

Please note that including the two separate binary attributes plus the interaction between them in the model is mathematically identical as recoding into a single attribute with 4 levels.
answered Jul 13, 2015 by Bryan Orme Platinum Sawtooth Software, Inc. (142,515 points)
thank you for your help!
...