I find it odd that so few people who post a problem complete the loop with a 'tick'. Even if they don't do that, it would be useful if they follow suggestions and cure the snag, that they give feedback as to which idea cured the problem. How can they be persuaded?
Maybe if they changed the colour of the resolved button it might help. The dull grey colour looks like a dead button and although they tick the box they do not press the resolved button. How do I know. Because I used to do the same when I first started using the PCA forum.
we used to email people once a month, asking them to tick their threads if resolved. It was effective for a while, but after a time we started receiving complaints that we were harassing people, so we discontinued the practice.