Classification of skills based on job ads I have around 1,000 job ads in the filed of IT (in excel file). I want to find the skills which are mentioned in each of ads. and then find the similar jobs based on skills.

My method: I created 12 categories Such as programming skills,  testing skills,  communication skills, network skills, ... . Each advertisement may belong to 3-4 categories. In this case, some said multi-variate classification or Multi label classification is useful. But I don't know how to do this kind of classification in RapidMiner.

1- Does anyone know how to do multi-variate classification or Multi label classification in RapidMiner? or is there another way?

2- Do you recommend "classification" in order to analysis required job skills? or another technique? 

3- Is there any better way to classify the skills which are stated in job ads?

I'm new in the field of text mining. Please let me know if you have any idea. Thanks
I don't know about RapidMiner, but for a beginner, Orange seems an awesome open-source tool for the job. 

Particularly if you want to do unsupervised learning, i.e. clustering. You'd probably want to preprocess your textual data in some bag of words model and save it as CSV, I guess.

I also hear Orange has a text mining add-on, but I haven't tried it yet.