Subjective quality of webpage loading: The impact of delayed and missing elements on quality ratings and task completion time

Webpage loading delays impact the quality perception, may cause frustration as well as annoyance, and can impact the users´ behavior. In addition, the quality perception can be further degraded by failures to load webpage components or, in the worst case, the failure to load the entire webpage. This impact depends on the actual implementation of the webpage and will in some cases not only delay the user´s task fulfillment, but also makes the task more complicated to solve. This paper presents the first empirical user study assessing the impact of failed to load elements in comparison to the delayed loading of webpages. The perceived quality is assessed by subjective quality ratings and the Task Completion Time (TCT). The results show that Page Load Time (PLT) and TCT alone are insufficient quality predictors when considering (partial) load failures. Therefore, established Web-QoE prediction models can be improved by also accounting for load failures.