João M. Santos 0001

dblp:163/4965 · DBLP profile ↗
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11ranked-venue papers
0as first author
7since 2021 · last 2025
0000-0001-6414-6891ORCID · verified

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Human-computer interaction and ubiquitous computing · 11 · 7 since 2021
YearPublicationVenuePosition
2025 When Personas Talk to You: Evaluating the Evolution of User Personas from Static Profiles to Conversational User Interfaces
abstract
The development of persona systems provides a possibility for end users to interact with different persona modalities. In a 54-participant randomized controlled experiment, we compare two persona interaction modalities, document and dialogue personas, both generated using AI approaches from survey data. Overall, dialogue personas appear to be perceived more favorably than document personas. However, document personas exhibit a wider range of perceptions, suggesting that experiences with document personas are more polarizing among users. The document personas had higher transparency and were perceived as more complete, but the task completion was perceived as more difficult, although the task success rate was higher. The dialogue personas were perceived as more usable, with a higher System Usability Scale score, and more enjoyable. Our findings provide critical insights into the increasingly important area of persona interaction modalities and the broad paradigm of human-persona interaction.
Ilkka Kaate, Joni Salminen, Soon-Gyo Jung, Trang Thi Thu Xuan, Jinan Y. Azem, João M. Santos 0001, Jim Jansen
Conference on Designing Interactive Systems6
2025 The 'fourth wall' and other usability issues in AI-generated personas: comparing chat-based and profile personas
abstract
Large Language Models (LLMs) are emerging as a powerful tool for AI-generated personas. This study evaluates the usability of AI-generated personas, comparing chat and profile formats. The findings indicate chat personas tend to be perceived more favourably, and profile personas exhibit greater variability in user perception. The increased difficulty and longer dwell time experienced by users with the profile persona, despite negative usability metrics, paradoxically resulted in better task performance. Usability issues indicate that many current limitations of AI, including verbosity, hallucinations, and empty rhetoric which was described as the persona having ‘no soul’, are inherited in AI-generated chat personas. However, there are also new issues. For one, the risk of information overload in an AI-generated profile persona implies that the AI does not consider human users’ cognitive limitations when designing the persona (but usability scores for profile personas increase with dwell time, implying that users get used to the longer format the more time they spend). Another is the ‘fourth wall’ effect of AI-generated chat personas in which the user feels they are talking to someone describing the persona rather than the persona itself. Future work could address the usability paradox and the fourth wall effect of using personas.CCS CONCEPTS Human-centered computing Human computer interaction (HCI)
Ilkka Kaate, Joni Salminen, Soon-Gyo Jung, João M. Santos 0001, Essi Häyhänen, Trang Xuan, Jinan Y. Azem, Jim Jansen
Behav. Inf. Technol.4
2025 Demographics do not matter?: Exploring the impact of gender and ethnicity on users' identification with AI-generated personas
abstract
Demographics are considered foundational information in most persona profiles. However, the effect of persona ethnicity and gender on designers’ identification with the persona has limited evaluation in the human-computer interaction literature. We conducted a study with 64 professional designers from the United States, Indian, Korean, and Mexican nationalities to investigate the effects of AI-generated persona ethnicity and gender on persona identification. The personas were created using Generative AI in the persona narratives and the persona video creation. The contribution of this work is that, against assumptions, neither persona ethnicity nor gender play a major role in persona identification among designers with different ethnic backgrounds. While there were some insinuations of ethnicity and gender in the open-ended feedback from the designers, the emergent qualitative themes describing persona identification were overwhelmingly universal and applicable regardless of ethnicity or gender. This implies that professional designers can effectively use personas with different demographic backgrounds, and effects of demographic attributes in personas leading to stereotyping are less impactful than presumed.
Ilkka Kaate, Joni Salminen, Soon-Gyo Jung, João M. Santos 0001, Kholoud Khalil Aldous, Essi Häyhänen, Jinan Y. Azem, Jim Jansen
Int. J. Hum. Comput. Stud.4
2023 The realness of fakes: Primary evidence of the effect of deepfake personas on user perceptions in a design task
abstract
Deepfakes, realistic portrayals of people that do not exist, have garnered interest in research and industry. Yet, the contributions of deepfake technology to human-computer interaction remain unclear. One possible value of deepfake technology is to create more immersive user personas. To test this premise, we use a commercial-grade service to generate three deepfake personas (DFs). We also create counterparts of the same persona in two traditional modalities: classic and narrative personas. We then investigate how persona modality affects the perceptions and task performance of the persona user. Our findings show that the DFs were perceived as less empathetic, credible, complete, clear, and immersive than other modalities. Participants also indicated less willingness to use the DFs and less sense of control, but there were no differences in task performance. We also found a strong correlation between the uncanny valley effect and other user perceptions, implying that the tested deepfake technology might lack maturity for personas, negatively affecting user experience. Designers might also be accustomed to using traditional persona profiles. Further research is needed to investigate the potential and downsides of DFs.
Ilkka Kaate, Joni Salminen, João M. Santos 0001, Soon-Gyo Jung, Rami Olkkonen, Jim Jansen
Int. J. Hum. Comput. Stud.3
2022 Using artificially generated pictures in customer-facing systems: an evaluation study with data-driven personas
abstract
We conduct two studies to evaluate the suitability of artificially generated facial pictures for use in a customer-facing system using data-driven personas. STUDY 1 investigates the quality of a sample of 1,000 artificially generated facial pictures. Obtaining 6,812 crowd judgments, we find that 90% of the images are rated medium quality or better. STUDY 2 examines the application of artificially generated facial pictures in data-driven personas using an experimental setting where the high-quality pictures are implemented in persona profiles. Based on 496 participants using 4 persona treatments (2 × 2 research design), findings of Bayesian analysis show that using the artificial pictures in persona profiles did not decrease the scores for Authenticity, Clarity, Empathy, and Willingness to Use of the data-driven personas.
Joni Salminen, Soon-Gyo Jung, Ahmed Mohamed Sayed Kamel, João M. Santos 0001, Jim Jansen
Behav. Inf. Technol.4
2022 Can Unhappy Pictures Enhance the Effect of Personas? A User Experiment
abstract
There has been little research into whether a persona's picture should portray a happy or unhappy individual. We report a user experiment with 235 participants, testing the effects of happy and unhappy image styles on user perceptions, engagement, and personality traits attributed to personas using a mixed-methods analysis. Results indicate that the participant's perceptions of the persona's realism and pain point severity increase with the use of unhappy pictures. In contrast, personas with happy pictures are perceived as more extroverted, agreeable, open, conscientious, and emotionally stable. The participants’ proposed design ideas for the personas scored more lexical empathy scores for happy personas. There were also significant perception changes along with the gender and ethnic lines regarding both empathy and perceptions of pain points. Implications are the facial expression in the persona profile can affect the perceptions of those employing the personas. Therefore, persona designers should align facial expressions with the task for which the personas will be employed. Generally, unhappy images emphasize realism and pain point severity, and happy images invoke positive perceptions.
Joni Salminen, Sercan Sengün, João M. Santos 0001, Soon-Gyo Jung, Jim Jansen
ACM Trans. Comput. Hum. Interact.3
2021 Picturing It!: The Effect of Image Styles on User Perceptions of Personas
abstract
Though photographs of real people are typically used to portray personas, there is little research into the potential advantages or disadvantages of using such images, relative to other image styles. We conducted an experiment with 149 participants, testing the effects of six different image styles on user perceptions and personality traits that are attributed to personas by the participants. Results show that perceptions of clarity, completeness, consistency, credibility, and empathy for a persona increase with picture realism. Personas with more realistic pictures are also perceived as more agreeable, open, and emotionally stable, with higher confidence in these assessments. We also find evidence of the uncanny valley effect, with realistic cartoon personas experiencing a decrease in the user perception scores.
Joni Salminen, Soon-Gyo Jung, João M. Santos 0001, Ahmed Mohamed Sayed Kamel, Jim Jansen
CHI3
2020 The effect of numerical and textual information on visual engagement and perceptions of AI-driven persona interfaces
abstract
In an experiment, we present 38 marketing and data analysts professionals with two online AI-driven persona interfaces, one using numbers and the other using text. We employ eye tracking, think-aloud, and a post-engagement survey for data collection to measure perception and visual engagement with the personas along 7 constructs. Results show that the use of numbers has a mixed effect on the perceptions and visual engagement of the persona profile, with job role as a determining factor on whether numbers/text affect end users for 2 of the constructs. The use of numbers has a significant positive effect on user perceptions of usefulness by analysts but a significantly negative effect on user perceptions of completeness for both marketers and analysts. The use of numbers decreases the perceived completeness of the personas for both marketer and analysts. This research has both theoretical and practical consequences for AI-driven persona development and their interface design, suggesting that the inclusion of numbers can have a desirable effect for certain roles but with possible negative effects on user perceptions.
Joni Salminen, Ying-Hsang Liu, Sercan Sengün, João M. Santos 0001, Soon-Gyo Jung, Jim Jansen
IUI4
2020 Does a Smile Matter if the Person Is Not Real?: The Effect of a Smile and Stock Photos on Persona Perceptions
abstract
We analyze the effect of using smiling/non-smiling and stock photo/non-stock photo pictures in persona profiles on four key persona perceptions, including credibility, likability, similarity, and willingness to use. For this, we collect data from an experiment with 2,400 participants using a 16-item survey instrument and multiple persona profile treatments of which half have a smiling photo/stock photo and half do not. The results from structural equation modeling, supplemented by a qualitative analysis, show that a smile enhances the perceived similarity with the persona, similar personas are more liked, and that likability increases the willingness to use a persona. In contrast, the use of stock photos decreases the perceived similarity with the persona as well as persona credibility, both of which are significant predictors to a willingness to use a persona. These professionally crafted stock-photos seem to diminish the sense of identification with the persona. The above effects are consistent across the tested ages, genders, and races of the persona picture, although the effect sizes tend to be small. The results suggest that persona creators should use smiling pictures of real people to evoke positive perceptions toward the personas. In addition to presenting quantitative evidence on the predictors of willingness to use a persona, our research has implications for the design of persona profiles, showing that the picture choice influences individuals’ persona perceptions even when the other persona information is identical.
Joni Salminen, Soon-Gyo Jung, João M. Santos 0001, Jim Jansen
Int. J. Hum. Comput. Interact.3
2020 Persona Transparency: Analyzing the Impact of Explanations on Perceptions of Data-Driven Personas
abstract
Computational techniques are becoming more common in persona development. However, users of personas may question the information in persona profiles because they are unsure of how it was created. This problem is especially vexing for data-driven personas because their creation is an opaque algorithmic process. In this research, we analyze the effect of increased transparency – i.e., explanations of how the information in data-driven personas was produced – on user perceptions. We find that higher transparency through these explanations increases the perceived completeness and clarity of the personas. Contrary to our hypothesis, the perceived credibility of the personas decreases with the increased transparency, possibly due to the technical complexity of the persona profiles disrupting the facade of the personas being real people. This finding suggests that explaining the algorithmic process of data-driven persona creation involves a “transparency trade-off”. We also find that the gender of the persona affects the perceptions, with transparency increasing perceived completeness and empathy of the female persona, but not for the male persona. Therefore, transparency may specifically assist in the acceptance of female personas. We provide practical implication for persona creators regarding transparency in persona profiles.
Joni Salminen, João M. Santos 0001, Soon-Gyo Jung, Motahhare Eslami, Jim Jansen
Int. J. Hum. Comput. Interact.2
2020 Persona Perception Scale: Development and Exploratory Validation of an Instrument for Evaluating Individuals' Perceptions of Personas
Joni Salminen, João M. Santos 0001, Haewoon Kwak, Jisun An, Soon-Gyo Jung, Jim Jansen
Int. J. Hum. Comput. Stud.2