Powerful and consistent analysis of likert-type ratingscales

Likert-type scales are used extensively during usability evaluations, and more generally evaluations of interactive experiences, to obtain quantified data regarding attitudes, behaviors, and judgments of participants. Very often this data is analyzed using parametric statistics like the Student t-test or ANOVAs. These methods are chosen to ensure higher statistical power of the test (which is necessary in this field of research and practice where sample sizes are often small), or because of the lack of software to handle multi-factorial designs nonparametrically. With this paper we present to the HCI audience new developments from the field of medical statistics that enable analyzing multiple factor designs nonparametrically. We demonstrate the necessity of this approach by showing the errors in the parametric treatment of nonparametric data in experiments of the size typically reported in HCI research. We also provide a practical resource for researchers and practitioners who wish to use these new methods

Means based adaptive persuasive systems

Large differences in individual responses to persuasive strategies suggest the need for systems that rely on persuasion profiles: estimates of an individual user's susceptibility to different persuasive strategies. Establishing an empirical ground supporting decisions regarding user involvement can provide valuable guidelines for the design of such systems. We describe two studies examining the effects of choice, disclosure, and multiple strategy usage on user compliance to persuasive attempts. We show that involving users in the selection of a specific influence strategy can increase compliance, while disclosing the persuasive intent can reduce compliance. Furthermore, we demonstrate that it is not only feasible, but optimal to choose the single correct influence strategy for a given context; even more so than implementing multiple relevant and congruent influence attempts

The effects of familiarity and similarity on compliance in social networks

Item does not contain fulltextAdvertisers on social network sites often use recommendations by others in a user's networks to endorse products. While these familiar others are hypothesised to be more effective in influencing users than unfamiliar others, there is a catch: familiarity does not necessarily ensure similarity to the familiar person, a potential problem because the combination of familiarity and dissimilarity has been hypothesised to lead to lowered compliance. In an experiment (N = 44), we test people's compliance to similar and dissimilar familiar others in an online environment: we show that in both cases, familiarity leads to increased compliance. The work highlights the importance of familiarity on interpersonal influence and suggests that gaining familiarity, even in situations of dissimilarity, can be an effective means to increase the impact of advertisements and marketing campaigns in social media.14 p

The effects of familiarity and similarity on compliance in social networks

Advertisers on social network sites often use recommendations by others in a user's networks to endorse products. While these familiar others are hypothesised to be more effective in influencing users than unfamiliar others, there is a catch: familiarity does not necessarily ensure similarity to the familiar person, a potential problem because the combination of familiarity and dissimilarity has been hypothesised to lead to lowered compliance. In an experiment (N = 44), we test people's compliance to similar and dissimilar familiar others in an online environment: we show that in both cases, familiarity leads to increased compliance. The work highlights the importance of familiarity on interpersonal influence and suggests that gaining familiarity, even in situations of dissimilarity, can be an effective means to increase the impact of advertisements and marketing campaigns in social media

Australian Veterinary History Record No. 31

Australian Veterinary Associatio

Can you be persuaded? Individual differences in susceptibililty to persuasion

Persuasive technologies are growing in popularity and many designers create systems which intentionally change users attitudes or behaviors. This study shows that peoples individual differences in susceptibility to persuasion, as implemented using the six persuasion principles proposed by Cialdini 2, relates to their compliance to a persuasive request which is accompanied by a persuasive cue. This result is a starting point for designers to start incorporating individual differences in susceptibility to persuasive cues in their adaptive persuasive systems

Adaptive persuasive systems:A study of tailored persuasive text messages to reduce snacking

This article describes the use of personalized short text messages (SMS) to reduce snacking. First, we describe the development and validation (N = 215) of a questionnaire to measure individual susceptibility to different social in¿uence strategies. To evaluate the external validity of this Susceptibility to Persuasion Scale (STPS) we set up a two week text-messaging intervention that used text messages implementing social in¿uence strategies as prompts to reduce snacking behavior. In this experiment (N = 73) we show that messages that are personalized (tailored) to the individual based on their scores on the STPS, lead to a higher decrease in snacking consumption than randomized messages or messages that are not tailored (contra-tailored) to the individual. We discuss the importance of this ¿nding for the design of persuasive systems and detail how designers can use tailoring at the level of social in¿uence strategies to increase the effects of their persuasive technologies. Keywords: Persuasion, social in¿uence, personalization, tailoring, persuasion pro¿lin

Behaviours and preferences when coordinating mediated interruptions: social and system influence

There is a growing interest in technologies for supporting individuals to manage their accessibility for interruptions. The applicability of these technologies is likely to be influenced by social relationships between people. This paper describes an experiment that examines interplay between a working relationship of an interruptor and an interruptee and two different system approaches to handle interruptions. We tested how system behaviour and the social relationship between the actors influence their interruption behaviours. Our results are consistent with prior research on the importance of relational benefit to understanding interruption. We found that interruptors were far more likely to be considerate of interruptees' activities, when they both shared a common goal. We have extended those findings by showing that interruptees display similar behaviours to those presented by interruptors. The results regarding the systems’ influence show a clear trend towards the positive effect of the Automatic system on peoples’ interruption behaviours which is based on: (i) visible interruption costs, (ii) social tension and (iii) system preference. We think that the results of this experiment translated into design implications can prove helpful in informing the design of computer–mediated solutions supporting interruption handling

Adaptive persuasive systems: A study of tailored persuasive text messages to reduce snacking

This article describes the use of personalized short text messages (SMS) to reduce snacking. First, we describe the development and validation (N = 215) of a questionnaire to measure individual susceptibility to different social in¿uence strategies. To evaluate the external validity of this Susceptibility to Persuasion Scale (STPS) we set up a two week text-messaging intervention that used text messages implementing social in¿uence strategies as prompts to reduce snacking behavior. In this experiment (N = 73) we show that messages that are personalized (tailored) to the individual based on their scores on the STPS, lead to a higher decrease in snacking consumption than randomized messages or messages that are not tailored (contra-tailored) to the individual. We discuss the importance of this ¿nding for the design of persuasive systems and detail how designers can use tailoring at the level of social in¿uence strategies to increase the effects of their persuasive technologies. Keywords: Persuasion, social in¿uence, personalization, tailoring, persuasion pro¿lin

Two acts of social intelligence : the effects of mimicry and social praise on the evaluation of an artificial agent

This paper describes a study of the effects of two acts of social intelligence, namely mimicry and social praise, when used by an artificial social agent. An experiment (N = 50) is described which shows that social praise—positive feedback about the ongoing conversation—increases the perceived friendliness of a chat-robot. Mimicry—displaying matching behavior—enhances the perceived intelligence of the robot. We advice designers to incorporate both mimicry and social praise when their system needs to function as a social actor. Different ways of implementing mimicry and praise by artificial social actors in an ambient persuasive scenario are discussed. Keywords: Ambient Intelligence – Attitude change – Persuasion – Friendliness – Chat-robot – Mimicry – Praise – Social intelligenc