Konstantinos Tsiakas

Dr. Konstantinos Tsiakas

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 May 2018 in Technologies
Verified
Journal Article
Open access
PDF file
KTKonstantinos Tsiakas
Konstantinos Tsiakas
MAMaher Abujelala
Maher Abujelala
FMFillia Makedon
Fillia Makedon
Socially-Assistive Robotics (SAR) has been extensively used for a variety of applications, including educational assistants, exercise coaches and training task instructors. The main goal of such systems is to provide a personalized and tailored session that matches user abilities and needs. While objective measures (e.g., task performance) can be used to adjust task parameters (e.g., task difficulty), towards personalization, it is essential that such systems also monitor task engagement to personalize their training strategies and maximize the effects of the training session. We propose an Interactive Reinforcement Learning (IRL) framework that combines explicit feedback (task performance) with implicit human-generated feedback (task engagement) to achieve efficient personalization. We illustrate the framework with a cognitive training task, describing our data-driven methodology (data collection and analysis, user simulation) towards designing our proposed real-time system. Our data analysis and the reinforcement learning experiments on real user data indicate that the integration of task engagement as human-generated feedback in the RL mechanism can facilitate robot personalization, towards a real-time personalized robot-assisted training system.

8 July 2024
Verified
Conference Paper
Open access
ZZZhengquan Zhang
Zhengquan Zhang
KTKonstantinos Tsiakas
Konstantinos Tsiakas
CSChristina Schneegass
Christina Schneegass
In human communication, responding to a question very slowly or quickly influences our trust in the answer. As chatbots evolve to increasingly mimic human speech, response speed can be artificially varied to create certain impressions on users. However, studies remain inconclusive, potentially due to the absence of contextual cues that allow for interpretation of the delay. Thus, this study explores textual explanations that justify the instant and dynamic – dependent on answer length – response delays. We derive five design variations based on prior work and evaluate their impact on the chatbot’s perceived social presence and transparency (N = 10). In a between-subject online study (N = 194), we then evaluate the influence of the highest-rated justification on users’ perceptions of chatbot transparency, social presence, and trust for the two delay conditions. Results demonstrate that while such justifications enhance perceived transparency and trust in the immediate response scenario, they show no effect in the dynamic delay context.

2 August 2024 in ACM Transactions on Interactive Intelligent Systems
Verified
Journal Article
Open access
KTKonstantinos Tsiakas
Konstantinos Tsiakas
DMDave Murray-Rust
Dave Murray-Rust
This article aims to develop a semi-formal representation for Human-AI (HAI) interactions, by building a set of interaction primitives which can specify the information exchanges between users and AI systems during their interaction. We show how these primitives can be combined into a set of interaction patterns which can capture common interactions between humans and AI/ML models. The motivation behind this is twofold: firstly, to provide a compact generalization of existing practices for the design and implementation of HAI interactions; and secondly, to support the creation of new interactions by extending the design space of HAI interactions. Taking into consideration frameworks, guidelines, and taxonomies related to human-centered design and implementation of AI systems, we define a vocabulary for describing information exchanges based on the model’s characteristics and interactional capabilities. Based on this vocabulary, a message passing model for interactions between humans and models is presented, which we demonstrate can account for existing HAI interaction systems and approaches. Finally, we build this into design patterns which can describe common interactions between users and models, and we discuss how this approach can be used toward a design space for HAI interactions that creates new possibilities for designs as well as keeping track of implementation issues and concerns.

13 December 2018 in Technologies
Verified
Journal Article
Open access
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KTKonstantinos Tsiakas
Konstantinos Tsiakas
Maria KyrariniMaria Kyrarini
Maria Kyrarini
VKVangelis Karkaletsis
Vangelis Karkaletsis
FMFillia Makedon
Fillia Makedon
OKOliver Korn
Oliver Korn
In this article, we present a taxonomy in Robot-Assisted Training; a growing body of research in Human–Robot Interaction which focuses on how robotic agents and devices can be used to enhance user’s performance during a cognitive or physical training task. Robot-Assisted Training systems have been successfully deployed to enhance the effects of a training session in various contexts, i.e., rehabilitation systems, educational environments, vocational settings, etc. The proposed taxonomy suggests a set of categories and parameters that can be used to characterize such systems, considering the current research trends and needs for the design, development and evaluation of Robot-Assisted Training systems. To this end, we review recent works and applications in Robot-Assisted Training systems, as well as related taxonomies in Human–Robot Interaction. The goal is to identify and discuss open challenges, highlighting the different aspects of a Robot-Assisted Training system, considering both robot perception and behavior control.

7 October 2016
Verified
Book Chapter
Closed access
PDF file
KTKonstantinos Tsiakas
Konstantinos Tsiakas
MDMaria Dagioglou
Maria Dagioglou
VKVangelis Karkaletsis
Vangelis Karkaletsis
FMFillia Makedon
Fillia Makedon

29 August 2022
Verified
Conference Paper
Closed access
MOMarieke van Otterdijk
Marieke van Otterdijk
HSHeqiu Song
Heqiu Song
KTKonstantinos Tsiakas
Konstantinos Tsiakas
IZIlka van Zeijl
Ilka van Zeijl
EBEmilia Barakova
Emilia Barakova
In social robotics, where people and robots interact in a social context, robot personality design is critical. Through voice, words, gestures, and nonverbal clues, social robots with expressive behaviors can display human-like actions, and the robot’s personality will ensure consistency. This research aims to create robot personalities expressed only by nonverbal cues. Differently from existing studies that test expressive behaviors with non-specialized participants, we look at how and why human movement analysts perceive distinct personalities in robots (introvert vs. extrovert) based on the robot’s movement and other dynamic features, such as joint position, head, and torso position, voice pitch, speed, and so on. We report the findings of a thematic analysis of the data obtained during a focus group with movement analysis experts who watched Pepper robot behaviors designed to be extrovert and introvert. Our findings lead to new guidelines for designing different robot movement features, including body symmetry, personality trait consistency, and social cue congruence during an interaction, all emphasized by the movement analyzers. Finally, we summarize the design principles for extrovert and introvert robot behaviors based on the combined findings of the focus group data analysis and literature review.