Wikipedia workshops are an important way for people to learn about the encyclopedia and contribute to Wikimedia UK's objectives. To measure that we want to collect people's user names so we can work out how many articles have been improved through the event.
It's also useful to think about gathering feedback on how things have gone. The office can process these for you, and send you along the results. Send them along to one of the programmes team.
Follow up is an important aspect of editing. The sign up form gives us permission to contact attendees afterwards, so we can send them resources like online training modules, or invite them contact trainers on their talk pages (if they're happy to do so).