Graphics Reference
In-Depth Information
You can also visually compare specific sequences. For example, you can see
if a team does a first-down pass followed by a second-down pass or whether
(for all teams) third down is more likely to feature a pass instead of a run.
This example is a naïve analysis of NFL plays because it does not take
into account the game state (for example, how many yards to reach a first
down or how many yards the team is away from scoring a touchdown).
These other factors will also have an impact on decision-making. However,
this example illustrates how you can use the approach to reveal patterns
in decisions and, in the case of football, how teams might determine a
defensive counter-strategy.
Note
To complete the story, New England and New York (both shown to be
strong passing teams) defeated Baltimore and San Francisco in their
respective conference finals. The Super Bowl pitted New England
against New York, whose decision trees show similar run and pass
behavior. In a closely contested game, the New York Giants won the
Super Bowl.
All the tree representations shown so far in this chapter depict only the tree.
However,asshowninsomeoftheexamples,thetreesmaybeextractedfrom
more complex graphs. Tree representations can be helpful for analyzing
these more complex graphs as well.
Website Trees and Effectiveness
Websites are complex containers that mix together a wide variety of content
andvariousinteractions. Eachclickbytheviewersonthewebsiterepresents
valuableinformation aboutwhatcontentisbeingviewed.Moreimportantly,
this information can also be used to understand what's working and what's
not working—that is, portions of a site that are effective and how people are
actually traversing the site.
Although a site may be made up of thousands or millions of pages, a site can
often be thought of as a hierarchy, and most websites have a site map that is
an explicit hierarchy showing the organization of the content of the site. All
the pages on a website slot into a particular node within a site map. Thus,
you can use a tree to represent all the content of the website as a hierarchy.
