Latent semantic analysis models on wikipedia and TASA

This paper introduces a collection of freely available Latent Semantic Analysis models built on the entire English Wikipedia and the TASA corpus. The models differ not only on their source, Wikipedia versus TASA, but also on the linguistic items they focus on: all words, content-words, nouns-verbs, and main concepts. Generating such models from large datasets (e.g. Wikipedia), that can provide a large coverage for the actual vocabulary in use, is computationally challenging, which is the reason why large LSA models are rarely available. Our experiments show that for the task of word-to-word similarity, the scores assigned by these models are strongly correlated with human judgment, outperforming many other frequently used measures, and comparable to the state of the art

A Sentence similarity method based on chunking and information content

This paper introduces a method for assessing the semantic similarity between sentences, which relies on the assumption that the meaning of a sentence is captured by its syntactic constituents and the dependencies between them. We obtain both the constituents and their dependencies from a syntactic parser. Our algorithm considers that two sentences have the same meaning if it can find a good mapping between their chunks and also if the chunk dependencies in one text are preserved in the other. Moreover, the algorithm takes into account that every chunk has a different importance with respect to the overall meaning of a sentence, which is computed based on the information content of the words in the chunk. The experiments conducted on a well-known paraphrase data set show that the performance of our method is comparable to state of the art. © 2014 Springer-Verlag Berlin Heidelberg

Experiments with semantic similarity measures based on LDA and LSA

We present in this paper experiments with several semantic similarity measures based on the unsupervised method Latent Dirichlet Allocation. For comparison purposes, we also report experimental results using an algebraic method, Latent Semantic Analysis. The proposed semantic similarity methods were evaluated using one dataset that includes student answers from conversational intelligent tutoring systems and a standard paraphrase dataset, the Microsoft Research Paraphrase corpus. Results indicate that the method based on word representations as topic vectors outperforms methods based on distributions over topics and words. The proposed evaluation methods can also be regarded as an extrinsic method for evaluating topic coherence or selecting the number of topics in LDA models, i.e. a task-based evaluation of topic coherence and selection of number of topics in LDA. © 2013 Springer-Verlag