Windschitl, P. D., & Wells, G. L. (1996). Measuring psychological uncertainty: Verbal versus numeric methods. Journal of Experimental Psychology: Applied, 2, 343-364.

The authors argue that alternatives to the traditional numeric methods of measuring people's uncertainty may prove to hold important advantages under some conditions. In 3 experiments, the authors compared verbal measures involving responses such as very likely, and numeric measures involving responses such as 80% chance. The verbal measures were found to show more sensitivity to various manipulations affecting psychological uncertainty (Experiment 1), to be better predictors of individual preferences among options with unknown outcomes (Experiment 2), and to be better predictors of behavioral intentions (Experiment 3). Results suggest that numeric measures tend to elicit deliberate and rule-based reasoning from respondents, whereas verbal measures allow for more associative and intuitive thinking. Given that there may be many types of situations in which human decisions and behaviors are not based on deliberate and rule-based thinking, numeric measures may misrepresent how individuals think about uncertainty in those situations.