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).