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What should be the correct type of a nominal attribute coded 0 and 1?
If an attribute has two possible values (their 'meaning' is nominal) but they are already coded as 0 and 1, then is it OK to just set the type as integer or should I set it as binominal and then transform it back to numeric in the process?
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Optionsrfuentealba Moderator, RapidMiner Certified Analyst, Member, University Professor Posts: 568 UnicornSure, it's just Addition, substraction, multiplication, division.Let's see if I can explain it better with a series of examples where numbers aren't about mathematicsMy passport number is P2312005. Would it make sense to do something with the "2312005" as a number? Nope.My car plate is BE7994. Would it make sense to do something with the number "7994"? Nope.When I push a key on my keyboard, that key contains a code which is subsequently translated into a character map. Let's suppose I press the key "A". It produces the decimal 65. Am I meant to use that decimal 65 to do something like making a sum? Nope.Those numbers don't fall in the category of "numeric", as aren't meant to be used in even basic mathematical operations such as addition, substraction, multiplication or division. It wouldn't make sense to know who has passport 2312006, for example. It's meaningless and you cannot extract value from the numeric form of these variables. In that case, this number should be used as a nominal, binominal or something similar (like an ID).On the other hand, I was born on February 22, 1983. Would you make calculations on those numbers? Sure! Calculate how old was I when I went to the school, discretize me into the "Millennials" bin, compare my age with the age of my peers as if it means anything, etc. You don't want a date to be a nominal, you want it to be a date, an amount of days, or something. That data cannot fall under the category of nominal, because they make sense as values and you can generate features out of these by applying mathematical operations or comparisons.Is it clearer?All the best,Rodrigo.8
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Thank you so much for your answer! Just one more thing: can you specify what you exactly mean by 'mathematical operations'?
Thank you!
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