One of the main features of the SparTag.us design is its Click2Tag technique, that allows users to simply point and click at words in a paragraph on a Web page in order to generate tags (which tag individual paragraphs). In comparison to the standard Type2Tag technique (i.e, think of tag words then type them in as tags) used on sites such as delicious.com, the Click2Tag technique involves fewer steps.

We conducted a laboratory study in which users were presented with texts to tag and then were later tested in a variety of memory experiments. The users were asked to user either Click2Tag or Type2Tag (there was also a no-tagging control condition). The Figure above summarizes the results: Click2Tag users produced more tags and spent less time doing so. In this Figure, reading time and tagging time are plotted on the x-axis and the tag production curves are from a theoretical model in  Information Foraging Theory (specifically the information patch model).

But are there cognitive costs or gains?

The Figure at left comes from a small eye tracking study conducted by Raluca Budiu. Users were reading and tagging single paragraphs while hooked up to a Tobii eye tracker. The heat maps indicate the amount of eye gaze time devoted to different portions of the text, with red indicating the high highest amounts. There are three conditions: Click2Tag, Type2Tag, and a no-tagging control. Notice that the Click2Tag users are devoting more gaze time to the text because they return their attention to the text in order to pick out words as tags.

Cognitive psychology predicts that this increased attention should increase the strength of memory for the original material, and this is borne out by tests of recognition memory.  The table below shows that recognition accuracy and response time to facts drawn from the original material is improved.

Summary

This study shows how simple changes in usability in a social computing system can yield benefits in terms of system-wide information production (tags) as well as individual learning and memory.