Table 1. Relationship of the Two Essays

5

Table 2. Features of a Session/Transaction

15

Table 3. Transactions Represented in Itemsets

19

Table 4. Comparison of Root Mean Squared Errors for Experiment

25

Table 5. Significance of The Comparison (paired t-test)

26

Table 6. Transactions Represented in Items

33

Table 7. Clustering Results for Experiment II

36

Table 8. The Entertainment Effect

38

Table 9. The Portal Effect

40

Table 10. Average Q and Q Variance at 5 Web Sites Selling CDs

73

Table 11. Average Q and Q Variance at 3 Web Sites Selling Books

74

Table 12. Comparisons Between Two Groups on Different Web Sites

74

Table 13. Probabilities Under 2 States

87

Table 14. Distribution of Transactions

88

Table 15. Variables in Experiment

97