Users browsing the web frequently encounter warning messages in situations deemed dangerous by browser vendors. Current implementations use similar messages in all such cases, which could result in a greater likelihood of user habituation. We investigate the effectiveness of tiered warning messages of varying severity levels and appearances in an attempt to more strongly convey risk and thereby increase adherence rates.

We conducted a study in which 20 participants first reacted to an unanticipated warning message and then, after learning the purpose of the study, 16 others. Most participants quickly ignored the warning in the first phase of the study, but in the second phase we found that our high severity tiered messages significantly outperformed the control messages in terms of user adherence and severity rating. Our low and medium severity tiered messages had significantly lower results in both areas. Additionally, users reacted more quickly to all tiered messages, on average, compared to the controls (whether dismissing them or adhering to them).