Cannot handle string attributes

I have a data set containing a string attribute and other double attributes not important in this moment. I need to use some classifiers to predict the value of my target class.

When i tried to connect my data set to the classifiers' learner, i had the error:"Cannot handle string attributes".

To solve this problem i used the "domain calculator" (as suggested in other topic) node before "Naive Bayes" and "SMO" nodes, but this way doesn't work with "NaiveBayesMultinominal" and "RProp MLP Learner" nodes that say "Cannot handle multi-valued nominal attributes " and "only double attributes" respectively.

How can i solve this problem? Any idea?

Thanks

 

Hi Craig, 

It sounds like the methods you are trying to use in your classifiers do not support strings as descriptors.  Is there a sensible way you can translate your string to a number?  Alternatively, you could try using a different classifier such as a Decision Tree. 

Aaron