Extracting experimental parameter entities from scientific articles.

Systematic reviews are labor-intensive processes to combine all knowledge about a given topic into a coherent summary. Despite the high labor investment, they are necessary to create an exhaustive overview of current evidence relevant to a research question. In this work, we evaluate three state-of-the-art supervised multi-label sequence classification systems to automatically identify 24 different experimental design factors for the categories of Animal, Dose, Exposure, and Endpoint from journal articles describing the experiments related to toxicity and health effects of environmental agents. We then present an in depth analysis of the results evaluating the lexical diversity of the design parameters with respect to model performance, evaluating the impact of tokenization and non-contiguous mentions, and finally evaluating the dependencies between entities within the category entities. We demonstrate that in general, algorithms that use embedded representations of the sequences out-perform statistical algorithms, but that even these algorithms struggle with lexically diverse entities.