It seems some of the top voted answers do not have an accepted check. I haven't noticed this on the other stackexchange sites I visit. Is there a reason for this?
Yes - the most common include:
- Some askers do not realise that they should mark as accepted
- Some never come back after asking the question
- Sometimes none of the answers meet the OP's needs
Incorporating Mark's comment:
- Sometimes the poster is undecided between two very good answers
- And sometimes the asker has no idea about the subject ,and cannot judge whether it is the correct answer in spite of the upvotes...
- And sometimes a lot of upvotes are by people who are so clueless about the topic that they don't realize that they cannot judge whether it is the correct answer, but the asker does realize that it is not.
In short, votes are often popularity, accepted often means personal fit - neither always mean "correct".