I was recently handed a job, whereby somebody wanted to learn 'Web Design', after making contact, and a 3 hour session, it was obvious this person was not going to achieve their intended goal, ie know enough about web design and Dreamweaver to be comfortable in job application situation, immediately.
I left them with some homework to do and organised to return a few days later.
Upon my return, I had personally revisited Dreamweaver to familiarise myself with its new version and how it handled CSS. The client had made some progress on their own project, but was reluctant to admit it was an achievement.
Prior to my second visit, I had developed 2 exercises to help the person try and understand the relationship between HTML & CSS. The client limped through the first, but threw the towel in before I could even begin the second.
So, five hours of teaching in an external environment, and several hours of 'prep' had helped me understand Dreamweaver better, not sure about the client.
I'll just call it 5 hours of PD.