Abstract
The paper compares different heuristics that are used by greedy algorithms for constructing of decision trees. Exact learning problem with all discrete attributes is considered that assumes absence of contradictions in the decision table. Reference decision tables are based on 24 data sets from UCI Machine Learning Repository (Frank and Asuncion, 2010). Complexity of decision trees is estimated relative to several cost functions: depth, average depth, and number of nodes. Costs of trees built by greedy algorithms are compared with exact minimums calculated by an algorithm based on dynamic programming. The results associate to each cost function a set of potentially good heuristics that minimize it.