抄録

◎山岸祐己・斉藤和巳（静岡県大）

We propose a new item ranking method that is reliable and can efficiently identify high-quality items from among a set of items in review sites using their review scores which were rated and posted by users. Typical ranking methods rely only on either the number of reviews or the average review score. Some of them discount outdated ratings by using a temporal-decay function to make a fair comparison between old and new items. The proposed method reflects trust levels by incorporating a trust discount factor into spatio-temporal-decay function. We bring in the notion of z-score to accommodate the trust variance that comes from the number of reviews available, and propose a z-score version of our statistical model.