Evaluation Evaluation

  • Authors:
  • David M. W. Powers

  • Affiliations:
  • AILab, CSEM, Flinders University of South Australia, email: David.Powers@flinders.edu.au

  • Venue:
  • Proceedings of the 2008 conference on ECAI 2008: 18th European Conference on Artificial Intelligence
  • Year:
  • 2008

Quantified Score

Hi-index 0.02

Visualization

Abstract

Over the last decade there has been increasing concern about the biases embodied in traditional evaluation methods for Natural Language Processing/Learning, particularly methods borrowed from Information Retrieval. Without knowledge of the Bias and Prevalence of the contingency being tested, or equivalently the expectation due to chance, the simple conditional probabilities Recall, Precision and Accuracy are not meaningful as evaluation measures, either individually or in combinations such as F-factor. The existence of bias in NLP measures leads to the 'improvement' of systems by increasing their bias, such as the practice of improving tagging and parsing scores by using most common value (e.g. water is always a Noun) rather than the attempting to discover the correct one. In this paper, we will analyze both biased and unbiased measures theoretically, characterizing the precise relationship between all these measures.