Latent Confusion Analysis by Normalized Gamma Construction


Issei Sato, Hisashi Kashima, Hiroshi Nakagawa ;
Proceedings of the 31st International Conference on Machine Learning, PMLR 32(2):1116-1124, 2014.


We developed a flexible framework for modeling the annotation and judgment processes of humans, which we called “normalized gamma construction of a confusion matrix.” This framework enabled us to model three properties: (1) the abilities of humans, (2) a confusion matrix with labeling, and (3) the difficulty with which items are correctly annotated. We also provided the concept of “latent confusion analysis (LCA),” whose main purpose was to analyze the principal confusions behind human annotations and judgments. It is assumed in LCA that confusion matrices are shared between persons, which we called “latent confusions”, in tribute to the “latent topics” of topic modeling. We aim at summarizing the workers’ confusion matrices with the small number of latent principal confusion matrices because many personal confusion matrices is difficult to analyze. We used LCA to analyze latent confusions regarding the effects of radioactivity on fish and shellfish following the Fukushima Daiichi nuclear disaster in 2011.

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