Centering Theory for Evaluation of Coherence in Computer-Aided Summaries

AbstractThis paper investigates a new evaluation method for assessing the coherence of computer-aided summaries, justified by the inappropriacy of existing evaluation methods for this task. It develops a metric for Centering Theory (CT), a theory of local coherence and salience, to measure coherence in pairs of extracts and abstracts produced in a computer-aided summarisation environment. 100 news text summaries (50 pairs of extracts and their corresponding abstracts) are analysed using CT and the metric is applied to obtain a score for each summary; the summary with the higher score out of a pair is considered more coherent. Human judgement is also obtained to allow a comparison with the CT evaluation to assess the validity of the development of CT as a useful evaluation metric in computer-aided summarisation.