(IEEE) CGA Article – (Digitally) Inking in the 21st Century

Last year, I was approached by Jim Foley to transform my dissertation on the challenges facing pen computing into an article for the IEEE Computer Graphics and Applications magazine. This was a very interesting experience, especially when it came time to distill an entire thesis down into a few pages! The process of disseminating my work in a venue that doesn’t commonly focus on HCI or pen computing was a very good exercise, as it made me reflect on why my work was important to the body of research knowledge as a whole, and the importance of articulation and conciseness when writing.

The article is available here.


The ubiquity and mobility of contemporary computing devices has enabled users to consume content, anytime, anywhere. Yet, when we need to create content, touch input is far from perfect. When coupled with touch input, the stylus should enable users to simultaneously ink, manipulate the page, and switch between tools with ease, so why has the stylus yet to achieve universal adoption? The author’s thesis sought to understand the usability barriers and tensions that have prevented stylus input from gaining traction and reaching widespread adoption. This article in particular explores the limits of human latency perception and evaluates solutions to unintended touch.

Dissertation now online

Now that all of the research comprising my Dissertation has been published (see here, here, here, here, and here), I am happy to make it publicly available. If you would like to read my dissertation (its a tad long at 144 pages), a .pdf copy of my thesis can be found here. I am also super happy that I was lucky enough to receive the University of Alberta Faculty of Science Doctoral Dissertation Award for my research.

Yes, there was lots of pontificatation during the writing of my dissertation.

Although pens and paper are pervasive in the analog world, their digital counterparts, styli and tablets, have yet to achieve the same adoption or frequency of use. Digital styli should provide a natural, intuitive method to take notes, annotate, and sketch, but have yet to reach their full potential. There has been surprisingly little research focused on understanding why inking experiences differ so vastly between analog and digital media and amongst various styli themselves. To enrich our knowledge on the stylus experience, this thesis contributes a foundational understanding of the factors implicated in the varied experiences found within the stylus ecosystem today. 

The thesis first reports on an exploratory study utilizing traditional pen and paper and tablets and styli that observed quantitative and behavioural data, in addition to preferential opinions, to understand current inking experiences. The exploration uncovered the significant impact latency, unintended touch, and stylus accuracy have on the user experience, whilst also determining the increasing importance of stylus and device aesthetics and stroke beautification. The observed behavioural adaptations and quantitative measurements dictated the direction of the research presented herein. 

A systematic approach was then taken to gather a deeper understanding of device latency and stylus accuracy. A series of experiments garnered insight into latency and accuracy, examining the underlying elements that result in the lackluster experiences found today. The results underscored the importance of visual feedback, user expectations, and perceptual limitations on user performance and satisfaction. The proposed Latency Perception Model has provided a cohesive understanding of touch- and pen-based latency perception, and a solid foundation upon which future explorations of latency can occur. 

The thesis also presents an in-depth exploration of unintended touch. The data collection and analysis underscored the importance of stylus information and the use of additional data sources for solving unintended touch. The behavioral observations reemphasized the importance of designing devices and interfaces that support natural, fluid interaction and suggested hardware and software advancements necessary in the future. The commentary on the interaction – rejection dichotomy should be of great value to developers of unintended touch solutions along with designers of next-generation interaction techniques and styli.

The thesis then concludes with a commentary on the areas of the stylus ecosystem that would benefit from increased attention and focus in the years to come and future technological advancements that could present interesting challenges in the future.

GI 2015 Publication! The last of my dissertation to be published …

I am very happy to announce that the last work from my Dissertation is set to be published at Graphics Interface this year. The publication, “Hands, Hover, and Nibs: Understanding Stylus Accuracy on Tablets” reports on a two-stage user study that evaluated the role hand posture, the information available from the hover cursor, and nib diameters have on the user experience while inking. a user study that was conducted at Microsoft Research during my extended internship. Walter assisted me with the analysis and discussion sections of the work. Once the full paper is available, I will provide a link to it, but for now the abstract is below.


Although tablets and styli have become pervasive, styli have not seen widespread adoption for precise input tasks such as annotation, note-taking, algebra, and so on. While many have identified that stylus accuracy is a problem, there is still much unknown about how the user and the stylus itself influences accuracy. The present work identifies a multitude of factors relating to the user, the stylus, and tablet hardware that impact the inaccuracy experienced today. Further, we report on a two-part user study that evaluated the interplay between the motor and visual systems (i.e., hand posture and visual feedback) and an increasingly important feature of the stylus, the nib diameter. The results determined that the presence of visual feedback and the dimensions of the stylus nib are crucial to the accuracy attained and pressure exerted with the stylus. The ability to rest one’s hand on the screen, while providing comfort and support, was found to have surprisingly little influence on accuracy.


Unintended Touch in ToCHI – New Journal Publication from MSR Internship

Two days before my PhD defense, I found out that a manuscript that I submitted to ToCHI on unintended touch (aka palm rejection) was accepted for publication! The manuscript is entitled “Exploring and Understanding Unintended Touch during Direct Pen Interaction” (previously titled, “Is it Intended or Unintended? Palm Rejection during Direct Pen Interaction”)  details a data collection experiment and an algorithmic analysis of various possible solutions to unintended touch on tablets. The work was part of the larger collection of pen-based work that I performed while I was an intern at Microsoft Research (yippee! for publication #4 from my MSR time).

An example of unintended touch information from the perspective of a digitizer. The current stylus location is denoted in blue and the unintentional touch events from the palm and little finger are denoted in varying shades of orange.

The manuscript will not be published until December 2014, so here is the abstract:

The user experience on tablets that support both touch and styli is less than ideal, due in large part to the problem of unintended touch or palm rejection. Devices are often unable to distinguish between intended touch, i.e., interaction on the screen intended for action, and unintended touch, i.e., incidental interaction from the palm, forearm, or fingers. This often results in stray ink strokes and accidental navigation, frustrating users. We present a data collection experiment where participants performed inking tasks, and where natural tablet and stylus behaviors were observed and analyzed from both digitizer and behavioral perspectives. An analysis and comparison of novel and existing unintended touch algorithms revealed that the use of stylus information can greatly reduce unintended touch. Our analysis also revealed many natural stylus behaviors that influence unintended touch, underscoring the importance of application and ecosystem demands, and providing many avenues for future research and technological advancement.

GI 2014 Publication! The Pen is Mightier, Microsoft Research Internship paper #3

Rounding out today’s news is another Graphics Interface 2014 publication that I have forthcoming. This publication, “The Pen Is Mightier: Understanding Stylus Behaviour While Inking on Tablets” reports on a user study that was conducted at Microsoft Research during my extended internship. The study investigated the differences in hand posture, hand movements, writing size, and user preferences while participants were performing note-taking and sketching tasks using traditional pen and paper, a digital tablet with a passive stylus, and a digital tablet. Dr. Anoop Gutpa served as my Microsoft mentor during the project and Fraser and Walter assisted me with the analysis and discussion sections of the work. Once the full paper is available, I will provide a link to it.

Although pens and paper are pervasive in the analog world, their digital counterparts, styli and tablets, have yet to achieve the same adoption and frequency of use. To date, little research has identified why inking experiences differ so greatly between analog and digital media or quantified the varied experiences that exist with stylus-enabled tablets. By observing quantitative and behavioural data in addition to querying preferential opinions, the experimentation reaffirmed the significance of accuracy, latency, and unintended touch, whilst uncovering the importance of friction, aesthetics, and stroke beautification to users. The observed participant behaviour and recommended tangible goals should enhance the development and evaluation of future systems.