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Agents
The term "agent" is sometimes used (among its other uses) to refer to cross-tabs that are graphically displayed in a network and allow some conjunctions (i.e., ANDs). In this context the term agent is effectively equivalent to the term "field-value pair".
For instance, if we consider the cross-tab above, we may define 6 "agents" for the goal Profit:High and graphically show them as in Figure 8.
Figure 8.
Note that here the weights 100 and 50 are simply the percentages of times the values are associated with the goal, (i.e., they represent impact ratios, notprobabilities). Although it is possible to represent conjunctions here by adding nodes to the left of each circle, there are often too many possibilities and for larger data sets problems arise rather quickly.
Like other cross-tab techniques, when dealing with numeric values, agents have to break the numbers into fixed "codes", (e.g., break Age into three age classes: (1-30), (31-60), (61-100)). Of course, the data may hold patterns that overlap any of these ranges, (e.g., the range (27-34) and these will not be detected by the agent). And if the ranges selected are too small, there will be too many of them and larger patterns will be missed. Moreover, this inability to deal with numeric data causes problems with multidimensional data (Parsaye, 1997).
Copyright (C) 1997, Journal of Data Warehousing, December 1997 |
