Do People Prefer to Give Interval-Valued or Point Estimates and Why?

Abstract

Capturing interval-valued, as opposed to more conventional point-valued data, offers a potentially efficient method of obtaining richer information in individual responses. In turn, interval-valued data provide a strong foundation for subsequent fuzzy set based modelling-e.g., using the Interval Agreement Approach. In 2019, open-source software (DECSYS) was released to enable digital administration of interval-valued surveys using an ellipse response mode. This study follows on from an appraisal of this software and demonstration of practical value of the approach, reported last year, in one of many potential real-world applications (consumer preference research). A key ambition of ellipse-based interval elicitation is to maximise response efficiency-i.e., minimising workload and complexity in obtaining this richer information. User experience is therefore a vital consideration regarding potential for broader adoption. The present paper documents a direct empirical comparison between interval-valued response elicitation (using ellipses) and a conventional point-valued counterpart (using a Visual Analogue Scale), in terms of user experience during completion of a simple quantitative estimation task. We examine differences in perceived ease-of-use, unnecessary complexity and effective communication of desired responses, as well as overall liking-with positive outcomes for the interval-valued response mode in each case. We also report results of multiple regression analyses examining how the first three variables contribute to participants' overall liking of each response mode, as well as exploring differences driven by potentially important demographic factors (i.e., gender, age & native English speaking).