Hana Vrzakova

Dr. Hana Vrzakova


Research Focus & Metrics

Academic Career Length

15Years (2012-Present)

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

Representative Publications

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28 March 2012
Verified
Conference Paper
Open access
PDF file
RBRoman Bednarik
Roman Bednarik
HVHana Vrzakova
Hana Vrzakova
MHMichal Hradiš
Michal Hradiš
Interaction intent prediction and the Midas touch have been a longstanding challenge for eye-tracking researchers and users of gaze-based interaction. Inspired by machine learning approaches in biometric person authentication, we developed and tested an offline framework for task-independent prediction of interaction intents. We describe the principles of the method, the features extracted, normalization methods, and evaluation metrics. We systematically evaluated the proposed approach on an example dataset of gaze-augmented problem-solving sessions. We present results of three normalization methods, different feature sets and fusion of multiple feature types. Our results show that accuracy of up to 76% can be achieved with Area Under Curve around 80%. We discuss the possibility of applying the results for an online system capable of interaction intent prediction.

6 October 2019 in Cognitive Science
Verified
Journal Article
Open access
PDF file
MAMary Jean Amon
Mary Jean Amon
HVHana Vrzakova
Hana Vrzakova
SDSidney K. D'Mello
Sidney K. D'Mello
We hypothesize that effective collaboration is facilitated when individuals and environmental components form a synergy where they work together and regulate one another to produce stable patterns of behavior, or regularity, as well as adaptively reorganize to form new behaviors, or irregularity. We tested this hypothesis in a study with 32 triads who collaboratively solved a challenging visual computer programming task for 20 min following an introductory warm‐up phase. Multidimensional recurrence quantification analysis was used to examine fine‐grained (i.e., every 10 s) collective patterns of regularity across team members' speech rate, body movement, and team interaction with the shared user interface. We found that teams exhibited significant patterns of regularity as compared to shuffled baselines, but there were no systematic trends in regularity across time. We also found that periods of regularity were associated with a reduction in overall behavior. Notably, the production of irregular behavior predicted expert‐coded metrics of collaborative activity, such as teams' ability to construct shared knowledge and effectively negotiate and coordinate execution of solutions, net of overall behavioral production and behavioral self‐similarity. Our findings support the theory that groups can interact to form interpersonal synergies and indicate that information about system‐level dynamics is a viable way to understand and predict effective collaborative processes.

19 April 2018
Verified
Conference Paper
Open access
SPSeonwook Park
Seonwook Park
CGChristoph Gebhardt
Christoph Gebhardt
RRRoman Rädle
Roman Rädle
AFAnna Maria Feit
Anna Maria Feit
HVHana Vrzakova
Hana Vrzakova
OHOtmar Hilliges
Otmar Hilliges
Developing cross-device multi-user interfaces (UIs) is a challenging problem. There are numerous ways in which content and interactivity can be distributed. However, good solutions must consider multiple users, their roles, their preferences and access rights, as well as device capabilities. Manual and rule-based solutions are tedious to create and do not scale to larger problems nor do they adapt to dynamic changes, such as users leaving or joining an activity. In this paper, we cast the problem of UI distribution as an assignment problem and propose to solve it using combinatorial optimization. We present a mixed integer programming formulation which allows real-time applications in dynamically changing collaborative settings. It optimizes the allocation of UI elements based on device capabilities, user roles, preferences, and access rights. We present a proof-of-concept designer-in-the-loop tool, allowing for quick solution exploration. Finally, we compare our approach to traditional paper prototyping in a lab study.

6 April 2023 in World Neurosurgery
Verified
Journal Article
Open access
SPSami Puustinen
Sami Puustinen
HVHana Vrzakova
Hana Vrzakova
JHJoni Hyttinen
Joni Hyttinen
TRTuomas Rauramaa
Tuomas Rauramaa
PFPauli Fält
Pauli Fält
AEAntti-Pekka Elomaa
Antti-Pekka Elomaa
Hyperspectral imaging (HSI) has the potential to enhance surgical tissue detection and diagnostics. Definite utilization of intraoperative HSI guidance demands validated machine learning and public datasets that currently do not exist. Moreover, current imaging conventions are dispersed, and evidence-based paradigms for neurosurgical HSI have not been declared. We presented the rationale and a detailed clinical paradigm for establishing microneurosurgical HSI guidance. In addition, a systematic literature review was conducted to summarize the current indications and performance of neurosurgical HSI systems, with an emphasis on machine learning-based methods. The published data comprised a few case series or case reports aiming to classify tissues during glioma operations. For a multitissue classification problem, the highest overall accuracy of 80% was obtained using deep learning. Our HSI system was capable of intraoperative data acquisition and visualization with minimal disturbance to glioma surgery. In a limited number of publications, neurosurgical HSI has demonstrated unique capabilities in contrast to the established imaging techniques. Multidisciplinary work is required to establish communicable HSI standards and clinical impact. Our HSI paradigm endorses systematic intraoperative HSI data collection, which aims to facilitate the related standards, medical device regulations, and value-based medical imaging systems.

7 November 2019 in Proceedings of the ACM on Human-Computer Interaction
Verified
Journal Article
Open access
ASAngela E.B. Stewart
Angela E.B. Stewart
HVHana Vrzakova
Hana Vrzakova
CSChen Sun
Chen Sun
JYJade Yonehiro
Jade Yonehiro
CSCathlyn Adele Stone
Cathlyn Adele Stone
SDSidney K. D'MEllo
Sidney K. D'MEllo
Collaborative problem solving (CPS) is a crucial 21st century skill; however, current technologies fall short of effectively supporting CPS processes, especially for remote, computer-enabled interactions. In order to develop next-generation computer-supported collaborative systems that enhance CPS processes and outcomes by monitoring and responding to the unfolding collaboration, we investigate automated detection of three critical CPS process ? construction of shared knowledge, negotiation/coordination, and maintaining team function ? derived from a validated CPS framework. Our data consists of 32 triads who were tasked with collaboratively solving a challenging visual computer programming task for 20 minutes using commercial videoconferencing software. We used automatic speech recognition to generate transcripts of 11,163 utterances, which trained humans coded for evidence of the above three CPS processes using a set of behavioral indicators. We aimed to automate the trained human-raters' codes in a team-independent fashion (current study) in order to provide automatic real-time or offline feedback (future work). We used Random Forest classifiers trained on the words themselves (bag of n-grams) or with word categories (e.g., emotions, thinking styles, social constructs) from the Linguistic Inquiry Word Count (LIWC) tool. Despite imperfect automatic speech recognition, the n-gram models achieved AUROC (area under the receiver operating characteristic curve) scores of .85, .77, and .77 for construction of shared knowledge, negotiation/coordination, and maintaining team function, respectively; these reflect 70%, 54%, and 54% improvements over chance. The LIWC-category models achieved similar scores of .82, .74, and .73 (64%, 48%, and 46% improvement over chance). Further, the LIWC model-derived scores predicted CPS outcomes more similar to human codes, demonstrating predictive validity. We discuss embedding our models in collaborative interfaces for assessment and dynamic intervention aimed at improving CPS outcomes.

23 March 2020
Verified
Conference Paper
Open access
HVHana Vrzakova
Hana Vrzakova
MAMary Jean Amon
Mary Jean Amon
ASAngela Stewart
Angela Stewart
NDNicholas D. Duran
Nicholas D. Duran
SDSidney K. D'MEllo
Sidney K. D'MEllo
Collaborative problem solving (CPS) in virtual environments is an increasingly important context of 21st century learning. However, our understanding of this complex and dynamic phenomenon is still limited. Here, we examine unimodal primitives (activity on the screen, speech, and body movements), and their multimodal combinations during remote CPS. We analyze two datasets where 116 triads collaboratively engaged in a challenging visual programming task using video conferencing software. We investigate how UI-interactions, behavioral primitives, and multimodal patterns were associated with teams' subjective and objective performance outcomes. We found that idling with limited speech (i.e., silence or backchannel feedback only) and without movement was negatively correlated with task performance and with participants' subjective perceptions of the collaboration. However, being silent and focused during solution execution was positively correlated with task performance. Results illustrate that in some cases, multimodal patterns improved the predictions and improved explanatory power over the unimodal primitives. We discuss how the findings can inform the design of real-time interventions for remote CPS.