Theophanis Tsandilas

Office 213

Université Paris-Saclay

91405 Orsay Cedex France

++33-169-156-834

I am research scientist (“Chargé de Recherche”) at Inria, member of the Ex)Situ team, and faculty member at the Université Paris-Saclay at the Interdisciplinary Laboratory of Digital Sciences (LISN - CNRS).

My research lies in the area of Human-Computer Interaction. I am especially interested in the following topics: sketching user interfaces, creativity-support and computer-assisted design tools, visualization design, gesture-based and pen-based interaction. I have also developed strong interest in statistical inference and modeling methods with applications in data analysis and visualization problems.

After a degree in Electrical and Computer Engineering at the National Technical University of Athens (Greece), I moved to Canada. I completed a M.Sc. and then a Ph.D. degree (2007) at the Department of Computer Science at the University of Toronto. I continued my research carreer in France, first as a postdoctoral follow and then as a faculty member.

I received my Habilitation (HDR) in July 2020.

news

Jun 15, 2024	We re-evaluated the Aligned Rank Transform (ART), which is frequently used for the analysis of experimental data. We found that ART is fundamentally flawed and recommend its abandonment. See our results and recommendations in our article submitted to the experimental track of JoVI. You can also find our open responses to the first reactions of ART’s main authors.

selected publications

vis/tvcg

DataGarden: Formalizing Personal Sketches into Structured Visualization Templates

Offenwanger, Anna, Tsandilas, Theophanis, and Chevalier, Fanny

IEEE Transactions on Visualization and Computer Graphics (VIS’24), Nov 2024

PDF Code Website DOI Bib

@article{offenwanger_vis:2024,
  title = {{DataGarden: Formalizing Personal Sketches into Structured Visualization Templates}},
  author = {Offenwanger, Anna and Tsandilas, Theophanis and Chevalier, Fanny},
  url = {https://exsitu-projects.github.io/timesplines},
  journal = {{IEEE Transactions on Visualization and Computer Graphics (VIS'24)}},
  publisher = {{Institute of Electrical and Electronics Engineers}},
  series = {TVCG 2025 (VIS 2024)},
  year = {2024},
  month = nov,
  keywords = {Personal visualization, Visualization template, Sketch input, Sketch-based visualization, Visualization by-example},
  website = {https://datagarden-git.github.io/datagarden},
  code = {https://github.com/datagarden-git/datagarden},
  pdf = {https://hal.science/hal-04664470/document},
  doi = {10.1109/TVCG.XXX.XXXXXX},
  abbr = vis/tvcg,
  bibtex_show = true,
  teaser = {datagarden.png},
  selected = true
}

vis/tvcg

TimeSplines: Sketch-Based Authoring of Flexible and Idiosyncratic Timelines

Offenwanger, Anna, Brehmer, Matthew, Chevalier, Fanny, and Tsandilas, Theophanis

IEEE Transactions on Visualization and Computer Graphics (VIS’23), Nov 2023

PDF Code Website DOI BibBest Paper Award

@article{offenwanger_vis:2023,
  title = {{TimeSplines: Sketch-Based Authoring of Flexible and Idiosyncratic Timelines}},
  author = {Offenwanger, Anna and Brehmer, Matthew and Chevalier, Fanny and Tsandilas, Theophanis},
  url = {https://exsitu-projects.github.io/timesplines},
  journal = {{IEEE Transactions on Visualization and Computer Graphics (VIS'23)}},
  publisher = {{Institute of Electrical and Electronics Engineers}},
  series = {TVCG 2024 (VIS 2023)},
  year = {2023},
  month = nov,
  keywords = {Temporal data, visualization, storytelling, sketch-based interfaces, lazy data binding.},
  website = {https://exsitu-projects.github.io/timesplines},
  code = {https://github.com/exsitu-projects/timesplines},
  pdf = {https://hal.science/hal-04236691/document},
  doi = {10.1109/TVCG.2023.3326520},
  abbr = vis/tvcg,
  bibtex_show = true,
  teaser = {timesplines.png},
  award = {Best Paper Award},
  selected = true
}

chi

Gesture Elicitation as a Computational Optimization Problem

Tsandilas, Theophanis, and Dragicevic, Pierre

In ACM Conference on Human Factors in Computing Systems (CHI), Apr 2022

PDF Code Website DOI BibHonorable Mention

@inproceedings{tsandilas_chi:2022,
  title = {{Gesture Elicitation as a Computational Optimization Problem}},
  author = {Tsandilas, Theophanis and Dragicevic, Pierre},
  url = {https://hal.archives-ouvertes.fr/hal-03559392},
  booktitle = {{ACM Conference on Human Factors in Computing Systems (CHI)}},
  address = {New Orleans, United States},
  year = {2022},
  month = apr,
  doi = {10.1145/3491102.3501942},
  keywords = {Gesture elicitation ; design optimization ; assignment problems ; optimization uncertainty ; learning curves ; bootstrap},
  website = {https://gelicopt.github.io/},
  pdf = {https://hal.archives-ouvertes.fr/hal-03559392/file/gelicopt.pdf},
  code = {https://github.com/gelicopt/gelicopt.github.io},
  hal_id = {hal-03559392},
  hal_version = {v1},
  selected = true,
  abbr = chi,
  teaser = {gelicopt.png},
  award = {Honorable Mention},
  bibtex_show = true
}

vldbj

ProS: Data Series Progressive k-NN Similarity Search and Classification with Probabilistic Quality Guarantees

Echihabi, Karima, Tsandilas, Theophanis, Gogolou, Anna, Bezerianos, Anastasia, and Palpanas, Themis

International Journal on Very Large Data Bases (VLDB Journal), Apr 2022

PDF Code Website DOI Bib

@article{vldbj:2022,
  title = {{ProS: Data Series Progressive k-NN Similarity Search and Classification with Probabilistic Quality Guarantees}},
  author = {Echihabi, Karima and Tsandilas, Theophanis and Gogolou, Anna and Bezerianos, Anastasia and Palpanas, Themis},
  journal = {{International Journal on Very Large Data Bases (VLDB Journal)}},
  publisher = {{Springer Nature}},
  numpages = {27},
  year = {2022},
  keywords = {Data Series, Similarity Search, k-NN Classification, Progressive Query Answering},
  pdf = {https://hal.science/hal-03888664/document},
  website = {https://helios2.mi.parisdescartes.fr/%7Ethemisp/pros/},
  code = {https://gitlab.inria.fr/progressivesimsearch/vldb-journal},
  doi = {10.1007/s00778-022-00771-z},
  teaser = {vldb22.png},
  abbr = vldbj,
  bibtex_show = true,
  selected = true
}

vis/tvcg

StructGraphics: Flexible Visualization Design through Data-Agnostic and Reusable Graphical Structures

Tsandilas, Theophanis

IEEE Transactions on Visualization and Computer Graphics (VIS’20), Feb 2021

PDF Code Website DOI Bib

@article{tsandilas_vis:2021,
  title = {{StructGraphics: Flexible Visualization Design through Data-Agnostic and Reusable Graphical Structures}},
  author = {Tsandilas, Theophanis},
  url = {https://hal.archives-ouvertes.fr/hal-02929811},
  journal = {{IEEE Transactions on Visualization and Computer Graphics (VIS'20)}},
  publisher = {{Institute of Electrical and Electronics Engineers}},
  series = {TVCG 2021 (InfoVis 2020)},
  volume = {27},
  number = {2},
  pages = {315-325},
  year = {2021},
  month = feb,
  keywords = {Visualization design ; graphical structures ; visualization grammars ; layout constraints ; infographics ; flexible data binding ; interaction design},
  website = {https://www.lri.fr/%7Efanis/StructGraphics/},
  code = {https://gitlab.inria.fr/structgraphics/code/},
  pdf = {https://hal.archives-ouvertes.fr/hal-02929811/file/StructGraphics-VIS20.pdf},
  doi = {10.1109/TVCG.2020.3030476},
  hal_id = {hal-02929811},
  teaser = {structgraphics.png},
  abbr = vis/tvcg,
  bibtex_show = true,
  selected = true
}

tochi

Fallacies of Agreement: A Critical Review of Consensus Assessment Methods for Gesture Elicitation

Tsandilas, Theophanis

ACM Transactions on Computer-Human Interaction (TOCHI), Jun 2018

PDF Code Website DOI Bib

@article{tsandilas_tochi:2018,
  author = {Tsandilas, Theophanis},
  title = {Fallacies of Agreement: A Critical Review of Consensus Assessment Methods for Gesture Elicitation},
  journal = {ACM Transactions on Computer-Human Interaction (TOCHI)},
  issue_date = {June 2018},
  volume = {25},
  number = {3},
  month = jun,
  year = {2018},
  issn = {1073-0516},
  pages = {18:1--18:49},
  articleno = {18},
  numpages = {49},
  website = {https://agreement.lri.fr/},
  code = {https://github.com/ephanis/TOCHI-supplementary},
  pdf = {https://hal.archives-ouvertes.fr/hal-01788775v4/document},
  url = {http://doi.acm.org/10.1145/3182168},
  doi = {10.1145/3182168},
  acmid = {3182168},
  publisher = {ACM},
  address = {New York, NY, USA},
  bibtex_show = true,
  teaser = {tochi18.png},
  abbr = tochi,
  keywords = {Gesture elicitation, agreement indices, agreement rates, bias, chance agreement, confidence intervals, content analysis, gestures, kappa coefficients, replication, statistics},
  selected = true
}

uist

Shape-Aware Material: Interactive Fabrication with ShapeMe

Wessely, Michael, Tsandilas, Theophanis, and Mackay, Wendy

In ACM Symposium on User Interface Software and Technology (UIST), Oct 2018

PDF Video DOI Bib

@inproceedings{wessely_uist:2018,
  title = {{Shape-Aware Material: Interactive Fabrication with ShapeMe}},
  author = {Wessely, Michael and Tsandilas, Theophanis and Mackay, Wendy},
  url = {https://hal.archives-ouvertes.fr/hal-01872776},
  booktitle = {{ACM Symposium on User Interface Software and Technology (UIST)}},
  address = {Berlin, Germany},
  publisher = {{ACM Press}},
  volume = {18},
  pages = {127-139},
  year = {2018},
  month = oct,
  doi = {10.1145/3242587.3242619},
  keywords = {sensing technologies ; personal fabrication ; shape-aware material ; physical modeling ; printed electronics ; ACM Classification Keywords H52 Information Interfaces and Presentation : User Inter-faces Author Keywords Personal fabrication ; Author Keywords Personal fabrication},
  pdf = {https://hal.archives-ouvertes.fr/hal-01872776v2/file/ShapeMe.pdf},
  video = {https://www.youtube.com/watch?v=Uq4eqt_ppTs},
  hal_id = {hal-01872776},
  teaser = {shapeme.png},
  bibtex_show = true,
  abbr = uist,
  selected = true
}

chi

How Novices Sketch and Prototype Hand-Fabricated Objects

Bousseau, Adrien, Tsandilas, Theophanis, Oehlberg, Lora, and Mackay, Wendy E.

In ACM Conference on Human Factors in Computing Systems (CHI), May 2016

PDF Video DOI Bib

@inproceedings{bousseau_chi:2016,
  title = {{How Novices Sketch and Prototype Hand-Fabricated Objects}},
  author = {Bousseau, Adrien and Tsandilas, Theophanis and Oehlberg, Lora and Mackay, Wendy E.},
  url = {https://hal.inria.fr/hal-01272187},
  booktitle = {{ACM Conference on Human Factors in Computing Systems (CHI)}},
  address = {San Jose, United States},
  organization = {{ACM}},
  year = {2016},
  month = may,
  doi = {10.1145/2858036.2858159},
  keywords = {Sketching ; physical prototyping ; fabrication ; collaborative design},
  pdf = {https://hal.inria.fr/hal-01272187/file/fabsketch_author.pdf},
  video = {https://vimeo.com/153102753},
  hal_id = {hal-01272187},
  teaser = {fabsketch.png},
  bibtex_show = true,
  abbr = chi,
  selected = true
}

chi

SketchSliders: Sketching Widgets for Visual Exploration on Wall Displays

Tsandilas, Theophanis, Bezerianos, Anastasia, and Jacob, Thibaut

In ACM Conference on Human Factors in Computing Systems (CHI), Apr 2015

PDF Video DOI BibHonorable Mention

@inproceedings{tsandilas_chi:2015,
  title = {{SketchSliders: Sketching Widgets for Visual Exploration on Wall Displays}},
  author = {Tsandilas, Theophanis and Bezerianos, Anastasia and Jacob, Thibaut},
  url = {https://hal.archives-ouvertes.fr/hal-01144312},
  booktitle = {{ACM Conference on Human Factors in Computing Systems (CHI)}},
  address = {Seoul, South Korea},
  organization = {{ACM}},
  pages = {3255-3264},
  year = {2015},
  month = apr,
  doi = {10.1145/2702123.2702129},
  keywords = {wall displays ; data visualization ; sketching interfaces},
  pdf = {https://hal.archives-ouvertes.fr/hal-01144312/file/paper%20copy.pdf},
  video = {https://vimeo.com/116862913},
  hal_id = {hal-01144312},
  teaser = {sketchsliders.png},
  bibtex_show = true,
  award = {Honorable Mention},
  abbr = {chi},
  selected = true
}

chi

Prospective Motor Control on Tabletops: Planning Grasp for Multitouch Interaction

Olafsdottir, Halla, Tsandilas, Theophanis, and Appert, Caroline

In ACM Conference on Human Factors in Computing Systems (CHI), Apr 2014

PDF Website Video DOI Bib

@inproceedings{olafsdottir_chi:2004,
  title = {{Prospective Motor Control on Tabletops: Planning Grasp for Multitouch Interaction}},
  author = {Olafsdottir, Halla and Tsandilas, Theophanis and Appert, Caroline},
  url = {https://hal.archives-ouvertes.fr/hal-00989345},
  booktitle = {{ACM Conference on Human Factors in Computing Systems (CHI)}},
  address = {Toronto, Canada},
  pages = {2893-2902},
  year = {2014},
  month = apr,
  doi = {10.1145/2556288.2557029},
  keywords = {Movement planning ; acquisition and manipulation ; range of motion ; end-state comfort effect ; multitouch ; tabletops},
  pdf = {https://hal.archives-ouvertes.fr/hal-00989345/file/TableTopMov-HAL.pdf},
  website = {http://insitu.lri.fr/Projects/ProspectiveMotorControl},
  video = {https://www.youtube.com/watch?v=DOwkHDybxU8},
  hal_id = {hal-00989345},
  teaser = {grasp.png},
  hal_version = {v1},
  bibtex_show = true,
  abbr = chi,
  selected = true
}

uist

The Drawing Assistant: Automated Drawing Guidance and Feedback from Photographs

Iarussi, Emmanuel, Bousseau, Adrien, and Tsandilas, Theophanis

In ACM Symposium on User Interface Software and Technology (UIST), Oct 2013

PDF Video DOI Bib

@inproceedings{iarussi_uist:2013,
  title = {{The Drawing Assistant: Automated Drawing Guidance and Feedback from Photographs}},
  author = {Iarussi, Emmanuel and Bousseau, Adrien and Tsandilas, Theophanis},
  url = {https://hal.inria.fr/hal-00840853},
  booktitle = {{ACM Symposium on User Interface Software and Technology (UIST)}},
  address = {St Andrews, United Kingdom},
  publisher = {{ACM}},
  year = {2013},
  month = oct,
  keywords = {Interactive drawing ; pen-based interfaces ; shape matching},
  pdf = {https://hal.inria.fr/hal-00840853v2/file/uist_lowres.pdf},
  doi = {10.1145/2501988.2501997},
  video = {https://www.youtube.com/watch?v=8Ynar1XM5H0},
  hal_id = {hal-00840853},
  teaser = {draw-assistant.png},
  bibtex_show = true,
  abbr = uist,
  selected = true
}

chi

Musink: Composing Music through Augmented Drawing

Tsandilas, Theophanis, Letondal, Catherine, and Mackay, Wendy

In ACM Conference on Human factors in Computing Systems (CHI), Apr 2009

PDF Code Video DOI BibBest Paper Award

@inproceedings{tsandilas_chi:2009,
  title = {{Musink: Composing Music through Augmented Drawing}},
  author = {Tsandilas, Theophanis and Letondal, Catherine and Mackay, Wendy},
  url = {https://hal.archives-ouvertes.fr/hal-00589698},
  booktitle = {{ACM Conference on Human factors in Computing Systems (CHI)}},
  address = {Boston, United States},
  pages = {819-828},
  year = {2009},
  month = apr,
  doi = {10.1145/1518701.1518827},
  keywords = {gesture interfaces ; Creativity ; interactive paper ; participatory design ; musical interfaces ; end-user programming ; gesture interfaces.},
  pdf = {https://hal.archives-ouvertes.fr/hal-00589698/file/CHI2009-hal.pdf},
  video = {https://vimeo.com/9535278},
  code = {https://www.lri.fr/%7Efanis/omusink/},
  hal_id = {hal-00589698},
  teaser = {musink.png},
  bibtex_show = true,
  award = {Best Paper Award},
  abbr = chi,
  selected = true
}