EWC2

Description

The EWC2 program compares the nDCG values of different variants of the BM25 with their corresponding EBM25 ones, checking whether following the EWC2 axiom improves the accuracy of the recommendations. This program can be used to generate Figure 1(b). The program only uses weighted variants of the algorithms (so they follow the EWC1 axiom).

Execution

The command to execute this program is the following:

java -jar contact-rec-axioms.jar ewc2 train test algorithmsFile outputDirectory directed recLength printRecs

where

• train: is the file containing the training graph.
• test: is the file containing the test edges.
• algorithmsFile: is the XML file containing the algorithms to compare (see conf. files). The only algorithm read will be BM25.
• outputDirectory a directory where to store the recommendations and the comparison file.
• directed: true if the graph is directed, false otherwise.
• recLength: the maximum number of recommended people for each target user (in our experiments, 10)
• printRecs: true if we want to store the recommendations, false if we just want the comparison file.

Outcome

After execution, if the printRecs option is set to true, the output directory will contain two subdirectories: one called bm25 which will contain the all the recommendations using the different BM25 variants, and another called ebm25 which will contain the recommenders when EBM25 is used. The base folder will have a ewc2.txt file showing the comparison betweenthe weighted BM25 and EBM25 variants.