When activties are organised for a participant, then the only evidence required will be the Assessor report at the end of the time frame.
'Formal' activities are where the participant does the activity with a group, and with the assessing adult.
When the activtiy is self directed by the participant, and will be done predominantely without the support of an assessing adult, participants will need to find ways to 'evidence' their participation and progress with the actitivty. In this instance it is often appropriate to add the DofE Manager as the assessor, but other staff (tutors) can be used, as well as family friends.
For example, here are some activities and some suggest types of evidence. The assessor just needs to be convinced that the relevant number of hours have been spent, and the participant has engaged - it is done primarily on trust