Databases Reference
In-Depth Information
matched well with a w ine selection, a d isproportionately small number
of entrée selections were purchased in conjunction with a wine selection.
In other words, the sale of all entrée selections had a lower than expected
aἀ nity with the sale of all wine selections. If this thinking were “in the
basket,” then the measured aἀ nity would be between a filet mignon and
a Burgundy wine. But, by thinking outside the basket a restaurant owner
noted that filet mignon, lobster, and all entrées in general were not cor-
relating well with wine in general.
Market Basket Analysis occurs outside the basket by incorporating
hierarchical groupings, geographic groupings, functional groupings…any
grouping that applies to the objects in an Itemset. Objects can be grouped
by the time of day the Itemset occurred, by the marketing campaign or
promotion in effect at the time of the Itemset, by the temperature of the
room of the Itemset, by the location at which the Itemset occurred, and so
on. These are the invisible objects in a market basket. You don't see them.
But they are there. Any property, attribute, group, or designation associ-
ated with an object can be included with that object in the Itemset. By
doing so, that property, attribute, group, or designation can be included in
the Itemset during Market Basket Analysis.
An object, property, attribute, group, or designation can be correlated
with any other object, property, attribute, group, or designation. By doing
so, the invisible becomes visible in an Itemset. This level of abstraction
also has an interesting interaction. If an enterprise is operating in bal-
ance, all levels of abstraction should approach its equilibrium aἀ nity with
all other levels of abstraction. For example, in a grocery store each aisle
should have the same level of aἀ nity for all other aisles. The aisle contain-
ing slow-moving products that constitute a small portion of overall sales
should have an aἀ nity with all other aisles of the store that corresponds
to that overall portion of sales. If, however, that slow-moving aisle has an
unexpectedly high aἀ nity for an aisle on the other side of the store, that
would be an opportunity to investigate that unexpectedly high level of
aἀ nity. Likewise, an aisle of a grocery store that carries staple products,
some of which you expect to find in every grocery cart, should have an
aἀ nity with all other aisles of the store that corresponds to that higher
portion of sales. If, like the aἀ nity of wine in a restaurant, an aisle of
that grocery store has an unexpectedly low aἀ nity with the fast-moving
staples aisle, that would also be an opportunity for investigation.
Of course, the Complement, Substitute, and Independent relationships
found in a market basket can also be found outside the market basket. The
