The Jam is absolutely not a competition, but it has a playful atmosphere. You might want to increase the feeling of ‘friendly competition’ at your Jam by choosing a winner or winners. You could announce them after the presentation of results—this would give your Jam a nice celebratory finish.
One good way is to let your mentors, experts or organisers each choose a favourite. This lets you emphasise the good points of several designs, without having to choose an overall winner.
You could also have a Jammer’s prize.
Some Jams have used real jam to vote with, the project with the most jam on their plate was the winner.
Other Jams used jars which would be stacked by the participants in front of their favourite project. The one with the highest tower would win.
Prizes might just be fun stuff, or sponsors might be able to assist with more substantial gifts. At the Global Service Jam 2011 (GSJ11), one sponsor of a local site helped make one design become real—and at the Global Sustainability Jam 2011 (GSusJ11) a sponsor gave professional consultancy to the winning team…