I have been an active member on this site for at least two years now. I have noticed this fact quite often that some days I see questions continuously from the same topic. On some days I see a group of questions which are easily solvable. On some days I find a group of questions from the topic I haven't heard before. My question is this. Is there some sort of filter or some methodology by which questions appear ? Or is this purely co incidental ? Or there are other reasons involved ?