More project mailbag

Got these emails and have noted my responses below each.

Dear Prof. Voleti,

Could you please share the Likert scale mappings for questions 23 through 26 regarding the perceptions about the current car brands?
Unlike the other questions, the mappings are not listed in the Word doc itself.

My reply:

OK. I usually take the neutral point on a likert as 0 and increment each side by 1 or -1. Those are the weights by which number of responses can be multiplied for a attribute-based brand map of sorts to be formed.

However, let me mention that the scaling and zero point are arbitrary. ANy consistent scaling will do and will produce similar brand maps like that one in lec 10, sec D. IMHO, of course.

Another mail came:

Hi Prof,

We started work on the analysis, and found that quite a few entries are incomplete. Wanted your suggestion on whether we should remove these entries. Also would be great if you could possibly suggest which entries to ignore and the basis for ignoring a field…

Thanks and Regards,

My reply:

Its your call.

Typically, missing data presents few, if any, happy options. In practice, it is best to remove rows with missing data. If there are too few rows to start with, impute the missing values. Failing that, replace missing values with column means.

IMO, the car dataset presents sufficient rows or observations to remove missing data rows.

Hope that helps.

Sudhir