Pre-processing text for Amazon Comprehend classification

Pre-processing the text for Amazon Comprehend is definitely not required, I have run Comprehend jobs without any pre-processing and got good results. Whether it is favourable is probably dependent on the specific dataset. I've never tried it and I'd be surprised if the results differed significantly, but the best way is probably to try it yourself with your dataset and compare the results.

Cheers, Heiko