Which NLP task is easier to begin with?

Question

Which one among the following NLP topics will be easier to work with?

1. Question answering
2. Paraphrase detection
3. Short text conversation
4. Author identification

Answer 1

The final one, Author identification. You don't need to have any understanding of the language you are dealing with, which the first three presuppose.

There is already a lot of literature on the topic; generally you identify features in texts, and map these onto a set of authors' known features. This can easily be done with cluster analysis or Machine Learning. So, it's not actually as NLP-heavy as the others.