Wednesday, August 31, 2011

Reaction: Understanding charts and graphs

The paper outlines the best practices in designing graphs and charts and formulates a set of conventions to identify good and bad designs; These guidelines can also be applied to evaluate the effectiveness of maps and diagrams.

The author clearly defines and contrasts the information (relations between entities) represented in graphs and charts. The paper contains an introduction to the analytic scheme which can be used to diagnose problems in a display. A display is defined to be a set of inter-related components.The primary components are background, framework, labels and specifier.

The components can be analysed at three levels -syntactic, semantic and pragmatic. Also, the author states several 'acceptability principles' that should not be violated. The sections describing the visual information processing and Goodman's theory of symbols are not clear and hard to comprehend.

The remainder of the paper identifies the various violations of the acceptability principles by considering Fig 3 as an example.

Though the author gives a detailed description of the associated concepts, it is not easy to understand them and it would have probably been easier if the same concepts were explained with better visual representations. The author also states that a violation of the acceptability principle does not necessarily mean a flawed design depending on the purpose of the graph. This would mean that in certain situations, the entire process of checking for compliance with the above mentioned conventions would be of little value in guaging the effectiveness of a chart or a graph.