I'm in the middle of my PhD and published 2 conference papers only with my supervisor, But i always want to have collaborations with other academic people in the field. Unfortunately i am a bit confused there!
I met people in conferences who were working on similar problems in the area, but i do not know how to initiate/request for collaboration? especially with a professor or a high level researcher.
Sometime when i read a paper related to my work, an idea for improvement of the proposed approach comes to my mind. But i put it somewhere in the shelf to get back to it later. But i'm not sure if it is a good idea to share it with the author or keep it to myself and work on it alone? In case of the first, should i contact the student author or the professor?
BTW, my field is computer science and i deal with machine learning and data analysis! so the most probable scenario which comes to my mind is getting some specific data from someone and working on that, but then it wouldn't be considered collaboration!
I am also in the middle of my PhD and have published more than 4 conference papers.
1) I tried to make a collaboration with another PhD student, whom I met in a conference. Basically, talking with them and finding out what they are doing now is a good start. I am currently discussing with a higher level researcher than me after having some online discussions in a facebook group, which I make. I try to introduce my papers and my expertise in my field, while trying to have some fruitful discussions in the group. You may also try to use researchgate to connect with other great researchers.
2) I have no experience about the second question.
3) I think that this can be considered as a collaboration. I am currently participating in a project as the researcher side with a company. The company provides data, while I and my team creates the algorithm. Then, the company will evaluate the result I get because they understand well about the practical situations and are able to give insightful comments if my results seems to be quite different with the real situation.
Hope it helps.