My experience using social bookmarking with medical students: #fail?

Experience with Delicious...
I have about 300 second year medical students independently researching topics related to families who they are visiting. 2 years I ago I started using Delicious to share resources with them- often forums where patients were discussing topics such as living with diabetes or being a parent.The advantage was that Delicious was public. It made it easy to share a group of links in Blackboard. I encouraged students to sign up and share their own links so that they could develop ideas about curating and sharing, but this was a secondary aim.  I was aware of 15 students who actually signed up to Delicious, and about half of those saved at least one bookmark. But they didn't really understand tagging and obviously didn't find use in it for themselves as they haven't done so again.  I was also a little frustrated that I couldn't comment on or discuss with students why they had identified a particular source.

Interestingly I have showed Delicious to two of my personal tutees and they have continued to use it. But I introduced this to them in a one-to-one meeting. How can I manage to show the benefits of social bookmarking to 300 students in a lecture (in 5-10 minutes)?

...then Diigo....
Last year I decided to try Diigo. This was because it had richer features and would allow discussion around a topic. I am perhaps over-protective of students, but because this task was around the families they were visiting, I was keen to make this a private community so that if they did inadvertently break patient confidentiality then less harm was done. I've written more here about the the process of setting up the group and some of the hiccups along the way. Towards the end (after 3 months) some students (three!) did start saving bookmarks (one saved 7 to his diigo account, and shared 3 of these with the group, the other two only saved one bookmark each).
58 students signed up to Diigo - and these are the only ones who could access the 187 items that had been saved to the group- mostly by me. If I shared a link like this http://groups.diigo.com/group/familycasestudy/content/tag/breastfeeding on Blackboard I was guaranteed to get a response from students saying that they couldn't access Diigo as they weren't a member. The process to join a closed group made it all more onerous.

Lessons learnt

• The rich features of Diigo including the ability to use an avatar were not used by students.
• A closed group makes things very much more complicated- and there was no evidence that students used the site in an inappropriate way- so open is better.
• Few students saved links themselves, but it is very useful for me to be able to easily share materials with them.

This year?

I need to be clear about why I am introducing social bookmarking to students. This is not (yet) part of a programme in digital literacy. I started using Delicious in the course simply because it was an easy way for me to share information with students. My expectations then started increasing which was why I chose to use Diigo in a much more complex way the next year. I don't think that I can say that the use of Diigo was a success. I don't actually use it myself very much despite these rich features so it is hard to recommend to others.

Should I go back to using Delicious. Yes- students will need to set up a Yahoo account in order to save links- and the features are not as rich.

Or, I continue to use Diigo but open it up- it might take off this year.

Or, I try out using Scholar, a social-bookmarking tool which is built into our VLE. So far I don't understand it which means I am unlikely to use it. (Why did they pick a name so close to Google Scholar which is completely different??)

It is perhaps harsh to call this a failure. I didn't set out with the deliberate aim of teaching students about social bookmarking. If I was then I would probably force them to set up accounts and to save and comment on others links.But, I would like students to understand what social bookmarking is about- and to see that it might be useful to them. 

In this situation what would you do? I will report back!

EDIT: Martin Weller writes about similar issues in encouraging researchers to adopt social media here http://www.typepad.com/services/trackback/6a00d8341c0c0e53ef0133f47b6207970b