Asia Pacific Journal of Information Systems (APJIS)

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Current Issue

Date	June 2026
Vol. No.	Vol. 36 No. 2
DOI	https://doi.org/10.14329/apjis.2026.36.2.347
Page	347~371
Title	Estimation of Missing Ratings for Items in Smaller Inventories
Author	Anand Va
Keyword	Inventory, Missing Ratings, Mechanism of Missingness, Recommender Systems
Abstract	In spite of a vast amount of extant research on recommender systems, two important questions did not receive much attention: 1. Should the missing ratings be estimated based on the mechanism of missingness ? and 2. Are the existing findings appropriate for businesses with relatively medium-sized inventories of up to 20,000 items ? Our study addresses these questions by experimenting with ten publicly available datasets. This unique 3 x 3 x 5 study explores three missingness mechanisms, three levels of missingness and five methods. With an empirics-first methodology, the study reveals the limitations of two fairly popular methods. It also offers a few striking results which should be of interest to businesses with medium-sized inventories.