Abstract
The principal aim of this paper is to bring the relatively little-known Hartley-like measure of uncertainty to the attention of readers of this journal. First, the reader is introduced to the classical Hartley measure of uncertainty, applicable to finite sets, and to the complementary Hartley-like measure of uncertainty, applicable to infinite sets. This is followed by an overview of some well-known applications of these measures to classical sets as well as standard fuzzy sets of possible alternatives. Applications of the Hartley-like measure to two types of non-standard fuzzy sets are then explored. This paper concludes with a discussion of two open research problems regarding the Hartley-like measure, solutions of which are essential for overcoming some practical limitations of this measure.