System Two Is Not Needed to Compute the Average of a Set of Lines at a Glance

The list of basic assessments is long, but not every possible attribute is assessed. For an example, look briefly at figur seven on the p d f. A glance provides an immediate impression of many features of the display. The failure of system one to compute the total length of a set of lines at a glance may look obvious to you. It is, in fact, an instance of an important limitation of that system. Because system one represents categories by a prototype or a set of typical exemplars, it deals well with averages and poorly with sums.