Knowledge Transfer for Out-of-Knowledge-Base Entities:A Graph Neural Network Approach
Table 3: Number of entities and triplets in the the OOKB datasets. The numbers of triplets include negative triplets.
['[EMPTY]', 'Head 1,000', 'Head 3,000', 'Head 5,000', 'Tail 1,000', 'Tail 3,000', 'Tail 5,000', 'Both 1,000', 'Both 3,000', 'Both 5,000']
In total, nine datasets were constructed with different numbers and positions of OOKB entities sampled from the test set. The process consists of two steps: choosing OOKB entities and filtering and splitting triplets. Choosing OOKB entities. To choose the OOKB entities, we first selected N=1,000, 3,000, and 5,000 triplets from the WordNet11 test file. For each of these three sets, we chose the initial candidates for the OOKB entities (denoted by I) in three different ways (thereby yielding nine datasets in total); these settings are called Head, Tail, and Both. In the Head setting, all head entities in the N triplets are regarded as candidate OOKB entities. The Tail setting is similar, but with the tail entities regarded as candidates. In the Both setting, all entities appearing as either a head or tail are the candidates. The final OOKB entities are the entities e∈I that appear in a triplet (e,r,e′) or (e′,r,e) in the WordNet11 training set, with e′∉I. Note that the entities h,t∉I are contained in the knowledge bases we already have and not in the OOKB entities. This last process filters out candidate OOKB entities that do not have any connection with the training entities. Filtering and splitting triplets. Using the selected OOKB entities, the original training dataset was split into the training dataset and the auxiliary datasets for the OOKB entity problem. That is, triplets that did not contain the OOKB entities were placed in the OOKB training set, and triplets containing one OOKB entity and one non-OOKB entity were placed in the auxiliary set. Triplets that contained two OOKB entities were discarded. For the test triplets, we used the same first N triplets in the WordNet11 test file that we used in Step 1, with the exception that the triplets that did not contain any OOKB entities were removed. For the validation triplets, we simply removed the triplets containing OOKB entities from the WordNet11 validation set. We denote each of the nine datasets by {Head,Tail,Both}-{1,000,3,000,5,000}, respectively, where the first part represents the position of OOKB entities and the second part represents the number of triplets used for generating the OOKB entities.