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Using 'Excluded' in Variables Coding in MBC


I am trying to understand what is the right way to code a binary availability variable. One of the options under Variable Codings is 'Excluded'. I haven't been able to find any information on what this coding does or when it should be used in either MBC manual or my notes from the MBC training.  Any guidance would be very much appreciated!
asked Aug 10, 2017 by Kate

1 Answer

0 votes
Excluding variables does just what the name implies - it excludes them entirely from the analysis. Usually this is used for items we included in the dataset, but do not want included in the model.

For instance, I'll sometimes manually add an "attribute" to an alternative-specific CBC design that is a placeholder for  levels that are entirely correlated with the levels shown in another attribute. I want to show the levels, so they appear in the design, but they don't actually vary independently so we don't need them in the analysis.

Another reason we might exclude a variable is if it was not chosen often enough to get a good read on its impact. This is especially true in MBC, where we might include menu items that just don't get selected very often.

For your binary variable, if you've coded it as 0 and 1, you would probably set it as "linear". If you've coded it as 1 and 2, then you could set it as "part worth" or "linear".
answered Aug 10, 2017 by Aaron Hill Gold Sawtooth Software, Inc. (12,245 points)