Background: It is difficult to assess whether community-dwelling frail older adults may remain pre-frail status or improve into a robust state without being directly checked by health care professionals. The health information perceived by older adults is considered to be one of best sources of potential concerns in older adult population. An online measurement system combined with item response theory (IRT) and computer adaptive testing (CAT) methods is likely to become a realistic approach to remotely monitor physical activity status of frail older adults. Objects: This article suggests an approach to provide a precise and efficient means of measuring physical activity levels of community-dwelling frail older adults. Methods: Article reviews were reviewed and summarized. Results: In comparison to the classical test theory (CTT), the IRT method is empirically aimed to focus on the psychometric properties of individual test items in lieu of the test as a whole. These properties allow creating a large item pool that can capture the broad range of physical activity levels. The CAT method administers test items by an algorithm that select items matched to the physical activity levels of the older adults. Conclusion: An online measurement system combined with these two methods would allow adequate physical activity measurement that may be useful to remotely monitor the activity level of community-dwelling frail older adults.

There are two purposes of this paper. One is to present a brief introduction to item response theory in conjunction with marketing research. The other is to present a review of current use of item response theory in representative marketing research journals. Several item response theory relevant papers were recently published in various marketing research journals. Because models under item response theory from simple to complex were used without any systematic introduction in marketing research, this paper briefly presents main concepts in item response theory. An encyclopaedia entry (Kim, 2015) and two graduate-level textbooks (Baker & Kim, 2004, 2017) are mainly referred and used for the first purpose. A content analysis was done for the second purpose with 28 item response theory relevant articles on marketing research journals. Articles are sorted based on the classification framework by Thissen and Steinberg (1986). Many articles reviewed relied on some type of unidimensional dichotomous item response theory models. Articles published recently within 10 years that used item response theory models were more complicated both mathematically and statistically than other previously published articles in marketing research journals. The taxonomic tabulations in this study should aid marketing researchers who are planning their continuous training in item response theory, and faculty who design or teach courses on marketing research methods for advanced undergraduate and graduate students.