4. Fuzzy Rule Generation In this paper, the linguistic variable values which are used for representing various input personalized parameters are low, low-medium and medium and high. Not-interested [NI], Weakly-interested [WI], Mediumly-interested [MI] and Strongly-interested [SI] are the output parameters respectively. A decision tree technique is used to generate fuzzy if-then rules for classifying the user interest. Before generating fuzzy rules the entire personalized user parameters are fuzzified and assigned linguistic labels based on their fuzzy membership values discussed from the previous section 3.3.
The fuzzified values for 20 Web pages visited by an individual are given in Table 6. The fuzzified values and its equivalent linguistic labels are represented in the Tables 7. Here LMD, MED, HGH labels represents Low-medium, Medium and High respectively
3.1. Fuzzy Decision tree based Fuzzy Rule Generation
Proposed work analyzes some possible variants of making classification rules from a fuzzy decision tree based on cumulative information. Decision trees, which make use of fuzzy sets and fuzzy logic for solving the introduced uncertainties, are called Fuzzy decision trees (FDTs) [4850]. Fuzzy decision trees mixes part of symbolic and sub-symbolic approaches. Fuzzy sets and symbolic logic permit modeling language-related uncertainties: whereas providing a symbolic framework for data quality. This work projected a brand new interpretation of Fuzzy C4.5, which relies on accumulative data estimate.
C4.5 is a propagation of ID3 that improves computing potency, deals with continuous values, handles attributes with missing values, avoids over fitting, and performs different functions [5154]. Fuzzified 524 Web pages of user data is provided as an input to C4.5 algorithm. Both testing and training data sets are divided using bootstrap approach in order to generate the accurate decision tree. The decision tree thus constructed is given in figure 6.
User given feedback label based sample training dataset is shown in Table 7.This approach correctly classified 497 instances out of 524 and incorrectly classified instances are 27 and also its mean absolute error, root mean squared error and relative absolute error, etc are shown in Table 8.
4.2. Fuzzy classification rule induction
In this empirical research work, we applied the above procedure on the various user attributes and generate 25 rules. The set of sample rules are shown in the Table 9. The same rules are applied for 10 different users in order for checking its completeness and consistency. Each user’s interest may vary according to their different and depends on several factors. This user model considers the user interest as the decision variable.
The attributes that are playing major role in the user interest classification and the notations that are used in this work is normalized and presented in Table 9 also C4.5 algorithm generated tree equivalent rules are represented in Figure 7.