Perhaps you could set up a form that would allow you to follow attendance with Collect. If this isn't a large scale operation:
1 - Set up a form with the name of all your participants (like you would normally do in Collect).
2 - You could make it a single screen to avoid having to go through 15-20 pages. For each participant, you have a "question", record yes/no for attendance.
So your form would look like this:;
Date : (Enter today's date)
Who is attending this trainning (you could even have a list of different trainnings)
Billy (choose yes/no)
Bob (choose yes/no)
Georges (choose yes/no)
etc....
So your output would be an Excel file, and every week you could sum up participation of each person (and/or total attendance for that session). Just set the "data_value" for you yes/no choice to 1/0, then the sum for each "variable" (person) would give you attendance since beginning/for that session/all session.
The drawback is that you would have to edit your form every time a new participant arrives, and that probably means you would have to manually merge your Excel files (because they would be different forms, thus from the moment you change the form_id you won't be able to add data to the older form). If you know VBA though you could code a little script in your Excel file to import the "new" form and merge them automatically.
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Another option is that instead of hard-coding the names in the forms, you could just set-up a bunch of "Participant 1", "Participant 2" instead of Billy/Bob/Georges, and then keep the equivalence of who is "Participant X" in a seperate registry. You have add a bunch of empty slots (e.g. have 50 spots in your form instead of the exact number), then you won't have to edit it. You could re-use that form for many different groups/trainings.
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If you want to use Survey then you could easily do this but then as Mitch said it's in Beta. I'm mostly proposing this in case it's a small operation and you don't want/can't to invest a whole lot in this.