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SecurityAutomated telephony Usability Empirical study Dialogue design a b s t r a c t This paper describes an experiment to investigate user perceptions of the usability and security of single-factor and two-factor authentication methods in automated telephone banking. In a controlled experiment with 62 banking customers a knowledge-based, singlefactor authentication procedure, based on those commonly used in the financial services industry, was compared with a two-factor approach where in addition to the knowledgebased step, a one-time passcode was generated using a hardware security token. Results were gathered on the usability and perceived security of the two methods described, together with call completion rates and call durations for the two methods. Significant differences were found between the two methods, with the two-factor version being perceived as offering higher levels of security than the single-factor authentication version; however, this gain was offset by significantly lower perceptions of usability, and lower ratings for convenience and ease of use for the two-factor version. In addition, the twofactor authentication version took longer for participants to complete. This research provides valuable empirical evidence of the trade-off between security and usability in automated systems. ª

This paper presents three experiments designed to empirically evaluate humanoid synthetic agents in electronic retail applications. Firstly, human-like agents were evaluated in a single e-retail application, a home furnishings service. The second experiment explored application dependency effects by evaluating the same human-like agents in a different e-retail application, a personalized CD service. The third experiment evaluated the effectiveness of a range of humanoid cartoon-like agents. Participants eavesdropped on spoken dialogues between a "customer" and each of the agents, which played the role of conversational sales assistants. Results showed participants expected a high level of realistic human-like verbal and nonverbal communicative behavior from the human-like agents. Overall ratings of the agents showed no significant application dependency: Two different groups of participants rated the human-like agents in similar ways in a different application. Further results showed participants have a preference for three-dimensional (3-D) rather than two-dimensional (2-D) cartoon-like agents and have a desire to interact with fully embodied agents.

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This study compared acoustic and electroglottographic (EGG) jitter from [a] vowels of 103 dysphonic speakers. The EGG recordings were chosen according to their intensity, signal-to-noise ratio, and percentage of unvoiced intervals, while acoustic signals were selected based on voicing detection and the reliability of jitter extraction. The agreement between jitter measures was expressed numerically as a normalized difference. In 63.1% (65/103) of the cases the differences fell within +/-22.5%. Positive differences above +22.5% were associated with increased acoustic jitter and occurred in 12.6% (13/103) of the speakers. These were, typically, cases of small nodular lesions without problems in the posterior larynx. On the other hand, substantial rises in EGG jitter leading to differences below -22.5% took place in 24.3% (25/103) of the speakers and were related to hyperfunctional voices, creaky-like voices, small laryngeal asymmetries affecting the arytenoids, or small-to-moderate glottal chinks. A clinically relevant outcome of the study was the possibility of detecting gentle laryngeal asymmetries among cases of large unilateral increase in EGG jitter. These asymmetries can be linked with vocal problems that are often overlooked in endoscopic examinations.

a b s t r a c tMulti-factor authentication involves the use of more than one mode in authentication processes and is typically employed to increase security compared to a fixed password (knowledge-based mode). This research compared three different eBanking authentication processes, a two-layer password (1-factor) method and two alternative 2-factor solutions. The 2-factor processes used One-Time-Passcodes (OTPs) delivered either via a small, single-use device or by text message to a mobile phone. The three authentication methods were compared in a repeated-measures experiment with 141 participants. Three user groups were balanced in the experiment to investigate the effect of experience (current users of the service) on perceptions of usability and security. Attitudes toward usability and observations were taken for each process. Other data gathered quality ratings, preferences and ranked comparisons regarding convenience and security issues. Both 2-factor methods scored significantly higher than the 1-factor method for eBanking authentication usability metrics overall, but experienced users gave higher scores to the 1-factor method they currently use. Overall preferences were spread evenly between the three methods. However, the majority of the participant sample perceived the 1-factor method they had most experience with as being the most secure and most convenient option. The results offer insight into customer attitudes important in their selection of authentication options: convenience, personal ownership and habitual experience of processes.

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