excellent tutorial available in the link below.. exactly what you want is there...

http://www.corequant.com/?p=1

Two video tutorials using Rapid-miner for sentiment analysis

https://www.youtube.com/watch?v=4EWXf3_0ta4

http://vimeo.com/62985704

Plenty of tutorial online, you can start from: 

https://www.youtube.com/watch?v=TNESlvXp47E

Hey.

Sorry all for late reply.

But really thank you so much for your help.

It helped me a lot.

@ Gt Vinodhini  , @Hadi Fanaee Tork ,  @Majdi Owda.

hi, i am doing text analysis in rapid miner on Ubuntu machine. I followed the process as explained over the link given below:

http://www.corequant.com/?p=1

i followed the above process on windows machine, it works well.

in case of Ubuntu machine, it worked well for one directory. but when we use both the directories one for positive and one for negative text files then it gave me the error described below:

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Reason: map failed

The given resource could not be read and parsed.please make sure the file is well formed and parsing parameters are specified correctly.

cause : Open WordNet Dictionary

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Thanks and Regards:

Sukh

you can see this

http://www.corequant.com/?p=1