Suppose you search in eBay on "Canon T4i" and you are looking for cameras that come with accessories bag, battery, flash, lens and memory card. Table 2 summarizes the title and included accessories of the cameras in the search result. The similarity between two products X and Y is determined by the function: sim(X,Y)=0.3 * simi(Xtitle,Y.title)+0.7 * sim2(Xaccessories,Y.accessories) siml(X.title,Y.title)-1/(d(X.title,Y.title)+1). d(X.title,Y.title) is defined as the minimum number of single-character insertions, deletions, or replacements required to convert X.title into Y.title, i.e., the edit distance between X.title and Ytitle. Example 1: To convert "ABC EFG" into "BCD EFG", we need to delete A (1 deletion) and insert D (1 insertion). Therefore, d("ABC EFG", "BCD EFG")-2 Example 2: To convert "ABC PQ" into "ABD PQ", we need to replace C with D (1 replacement). Hence, d"ABC PQ, "ABD PQ-1 sim2(X.accessories,Y.accessories) represents the Jaccard similarity between the sets X.accessories and Yaccessories. Example 3: Consider the query and Camera 1 sim2(query,C1)- bag, battery, flash, lens) |/I bag, battery, flash, lens, memory card | Determine 2-nearest neighbors of the query. Use the function sim(X,Y) as a measure to compute the similarity of the cameras. Table 2 Title Accessories C1 C2 C3 C4 C5 Canon T4i Digital SLR Canon T4i Digital DSLR Canon Digital Canon T4i Canon T4i DSLFR bag, battery, flash, lens battery, flash, lens, memory card bag, battery, lens battery, flash, lens bag, battery, flash, lens