The WordNet and word2vec alignment metrics are computed as follows, where S is a student response, R is one of a set of reference texts, W s and W r are content words in S and R, respectively, and   When R is one of a set of reference texts (e.g., one of multiple exemplars available for a given score point), we use the maximum similarity over available values of R. In our data, there are multiple exemplars per score point, but only one text (usually, a single sentence) per key concept.
we select the most similar exemplar response for each score level.