“Frequentists? How often do you see those?”

Although the arguments with the standard approach to PT go back to its earliest days (the decade around 1665), and have been repeated in each century since, in modern times the main criticisms have come from researchers in Artificial Intelligence. KPT does not adequately or intuitively represent all forms of uncertainty, in particular, uncertainty about uncertainty. As a consequence, Possibility theory and Dempster-Shafer Theory have arisen as alternatives to KPT. Although many of these alternative approaches can be shown to be formally equivalent to second- or higher-order versions of KPT (eg, they involve random variables distributed according to functions with parameters which are themselves random variables), humans typically find them more intuitive than KPT.