CAPTCHA Usability and Performance, How to Measure the Usability Level of Human Interactive Applications Quantitatively and Qualitatively?

Measuring the usability and user performance level of any products or services especially in the field of online and computer-based applications is a vital issue, which has been in the centre of attention for the researchers. One of the most common ways of measuring the usability and performance of any online interactive application or service is by conducting a comprehensive user study or by asking users to give their feedback on that particular product or application. In order to achieve valuable user feedback, a good quality survey and questionnaire needs to be designed in order to measure the usability and performance of the model quantitatively and qualitatively. In this paper, some of the most important elements involved in designing of online survey forms especially in the field of computer security and precisely web security have been investigated in order to measure the usability and performance level of different online security applications, such as CAPTCHAs or Human Interactive Proofs (HIPs), which are used to increase the security of online-based service providers.