Whereas sort actions only reorder the flights on screen, search actions actually add or remove flights from view. In a sense, this makes a search a stronger type of filter, as any flight that fails to meet the search criteria cannot be chosen. Figure 4 shows a distribution of the number of flights shown at the time of choice as a percentage of the potential number of flights shown if no search criteria were applied. Of the tasks where a search was performed, the median band is a showing of just 30-40% of potential flights. These reductions are quite large in absolute terms when some search tasks contain 24 potential flights. The distribution shows that the search tool is providing an effective way to reduce the size of the consideration set of alternatives. ts shown