Poster: Towards Measuring Warning Readability
Designing and writing warning messages can be considered a form of art that is often supported by engineering guidelines. A sizeable amount of research has evaluated different strategies to create effective warnings in the physical as well as the digital world [7, 5, 6] It has been recognised that the descriptive text provided in warning messages needs to be comprehensive and understandable by most computer users. In 2011, Bravo Lillo et al. [3] compiled a set of design guidelines and present the following rules for descriptive text: "describe the risk; describe consequences of not complying; provide instructions on how to avoid the risk; be brief; avoid technical jargon" Judging whether or not these goals are sufficiently met is however usually left to an expert's opinion or to testing through user studies. Consequently, there is considerable effort and knowledge involved in analysing and optimising warning messages. For over 60 years, educational research has developed and studied automatic measures to analyse text readability and suitability. Formulas, such as the Flesch Reading Ease, the Gunning Fog Index or the New Dale Chall Formula compiled from empirical analyses, allow a rough estimation of the number of years of education a reader has to have had in order to be able to comprehend a given text to a certain degree. The ongoing work presented in this poster examines the possibility of using automatic readability measures to support the analysis and creation of end user warning messages in computer software. We will present an initial analysis of browser security warnings using existing measures as well as a first explorative study of 15 students to analyse the applicability of these measures. To the best of our knowledge, there has not been any work investigating the application of readability measures for computer warning messages to date.