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Case Study: Stoichiometry Study, Fall 2005

Published January 4, 2006

Launch the stoichiometry tutor

In this innovative study, Carnegie Mellon University researchers Bruce McLaren, Dave Yaron, and Kenneth Koedinger utilized CTAT Flash tutors to investigate whether learning could be improved by personalized, informal language and worked examples in intelligent tutoring. For the first time, CTAT was used in a large-scale, web-based Pittsburgh Science of Learning Center (PSLC) study. The study, conducted at the University of British Columbia, tested and expanded the capabilities of the Cognitive Tutor Authoring Tools. As a result, many new features were added to CTAT and made publicly available.

The researchers employed a CTAT-developed delivery infrastructure titled TutorShop and a PSLC enabling technology known as PSLC DataShop to deliver chemistry tutors to the web and log student data, respectively. In this customized environment, CTAT made the following possible:

For stoichiometry, a sub-domain of chemistry that addresses the calculation of relationships between reactants and products in chemical reactions, the researchers required an interface that supported algebraic calculations. The Cognitive Tutor Authoring Tools were ideal for this task, providing enhanced problem solving through standard widgets, such as pull-down menus and text boxes. The researchers also needed technology that would work across a range of browsers and computers, since all of the subjects would be participating outside the lab setting. This is where the Flash tutors were especially desirable. According to NPD Research, Macromedia Flash already reaches 97.3% of Internet-connected PCs. For Flash tutors, the requirements are no more than the ubiquitous Flash player itself.

Long-distance logging of student interactions with the tutor was also essential. This was accomplished via PSLC's DataShop, a data repository and framework for collecting research results. DataShop also provided the researchers with easy to use analysis and visualization tools, and easy exporting to common data formats for use in programs like SPSS.

The results of the stoichiometry studies are presented in the following papers:

To learn more about the Stoichiometry Tutor and its use in studies go to the following page:

For more information on the PSLC DataShop, visit