🚀 go-pugleaf

Next Meeting:   Wednesday, November 16 at 2.00 p.m. in Sidney Smith R.570
Topic:          Graphs and psychophysics
Speaker:        Ian Spence
Synopsis:       Tufte, Macdonald-Ross, Cleveland and McGill, and others,
                recommend that we do not construct graphs with graph
                elements that have more dimensions than the data.  The use
                of boxes and cylinders, as well as volumes of other kinds, 
                is frowned upon, as is the use of graph elements that 
                require the observer to judge areas.  

                Such opinions are loosely based on results in traditional
                psychophysics, a branch of psychology that seeks to 
                investigate the relation between subjective experience
                and the physical magnitude of stimuli.  It is well known
                that judged length is proportional to physical length, but
                that judged areas or volumes are generally underestimated,
                with a power function providing a better description than
                a straight line.

                Until now, no one has determined the exponents of the 
                psychophysical function for common graphical elements, such 
                as lines, bars, pie and disk slices, boxes and cylinders.  
                An experiment that does this will be presented and 
                discussed, and a definitive answer to Tufte's question, 
                "Should we forego the 4000 lb chicken", will be given.