How social tagging appears to affect human memory?

Three weeks ago, I was at the ASIST 2007 Annual conference in Milwaukee, which had a special theme on Social Computing and Information Science. During one of the panels on Social Tagging, a question was raised on how tagging really affects memory and retrieval. I mentioned that the ASC group here at PARC has been doing some experiments on this, and briefly talked about the results, and many attendees at the conference (over 10 people) had asked for the pre-print, so here I'm blogging about it.

Raluca Budiu, who is a post-doc working in our group, has conducted some very interesting research with us on how tagging appears to affect human information processing. She studied two techniques for producing tags: (1) the traditional type-to-tag interface of typing keywords into a free-form textbox after reading a passage or article; (2) a PARC-developed click2tag interface that allows users to click on keywords in the paragraph to tag the content.

The experiment consisted of 20 subjects and 24 passages in a within-subject design. Participants had to first study passages and tag them, and then they performed memory tests on what they had actually read and tagged. The memory tasks were that, after tagging the content, they have to either (a) freely recall and type as many facts from the passages as possible; or (b) answer 6 true/false sentences in a recognition task.

As reported in the paper, the results suggest that:

• In the type-to-tag condition, users appears to elaborate what they have just read, and re-encoded the knowledge with keywords that might be helpful for later use. This appears to help the free-recall task (a) above. In other words, users seem to end up with a top-down process and induces them to schematize what they have learned.



• While in the click2tag condition, users appears to re-read the passages to pick out keywords from the sentences, and this appears to help them in their recognition tasks (b) above. In other words, users seem to use a bottom-up process that simply picked out the most important keywords from the passage.

Click here to download the technical report and pre-print (the highlights in the paper are mine).