Download to read offline
Uploaded byNiklas Elmqvist
Tracing and Sketching Performance using Blunt-tipped Styli on Direct-Touch Tablets
This study examined tracing and sketching performance using blunt-tipped styli on direct-touch tablets compared to using fingers. 14 participants performed tracing and sketching tasks with 3 different input methods. Tracing was faster, had fewer failures, and participants felt more comfortable using a blunt stylus compared to fingers. Sketches drawn with a blunt stylus were rated higher quality by crowdsourced voters. A follow up study with 6 participants directly compared blunt and sharp styli, finding sketches were selected 3 times more often when using a blunt stylus. The findings provide evidence that blunt styli can better support tracing and sketching tasks on direct-touch tablets compared to fingers or sharp styli.
Tracing and Sketching Performance using Blunt-tipped Styli on Direct-Touch Tablets
- 1. Tracing and SketchingPerformance using Blunt-tipped Styli on Direct-Touch Tablets Sriram Karthik Badam, Senthil Chandrasegaran Niklas Elmqvist, Karthik Ramani
- 2. Tablet computers: transitioningfrom paper 2
- 3. Digital medium: contentcreation 3
- 4.
- 5.
- 6. Digital design inputstyli * 6
- 7.
- 8. Typical product design Sketchprimitives Develop a model from primitives Improve quality by tracing over Can digital design tools replace paper for this? 8
- 9. Aspects of direct-touchsketching friction occlusion parallax familiarity 9
- 10. Related Work Accot andZhai (1999) Zabramski et al. (2011) 10
- 11. Study 14 participants (13 male,1 female) 3 medium + input multiple shapes 2 tasks Tracing Sketching 11
- 12. Tracing x 3 repetitions •Time taken for each trace • Failures to keep to the tunnel • Questionnaire x 3 media 12
- 13. What’s better? Tracing speed Fastto Slow * 7.27 sec 7.69 sec 8.58 sec 13 * significant with p-value <= .05
- 14. What’s better? Tracing failures Leastto Most 3 20 84 14
- 15. Tracing task -survey Comfortable Confident Accurate 14 14 14 12 10 10 5 2 1 15
- 16. Sketching x 3 repetitions x3 medium • Sketch Quality – Crowdsourced voting! • Questionnaire A B C D 16
- 17. What’s better? Sketch quality Highto Low * * significant with p-value <= 0.05 17
- 18.
- 19. Aspects Familiarity (self reported)occlusion friction parallax different* pen-paper different than tablet pen-paper different than tablet < < > < = 19
- 20. Findings Tracing speed Tracing failures(fewer) Sketch quality of cubes Sketch quality of cylinders * * * * * (*) significantly better performance than the unmarked media -----------------------------same--------------------------- 20
- 21. Blunt tipped vs.Sharp tipped styli 21
- 22. Follow-up 6 participants (5 male,1 female) 2 medium + input multiple shapes 2 tasks Tracing Sketching 22
- 23. Data collection • Timetaken for each trace • Failures to keep to the tunnel • Sketch Quality – expert voting (4 independent judges)! Tracing (5 shapes) Sketching (3 shapes) • Questionnaire • Questionnaire 23
- 24. What’s better? Tracing speed Fastto Slow 7.59 sec 7.71 sec 24
- 25. What’s better? Tracing failures Leastto Most 11 15 25
- 26. Tracing task -survey Comfortable Confident Accurate 5 3 2 4 5 5 26
- 27. What’s better? Sketch quality Highto Low • Sketches drawn with hard-tipped stylus were chosen three times more frequently 27
- 28. Sketching task -survey Comfortable Confident Accurate 5 4 2 3 3 4 28
- 29. Aspects familiarity occlusion friction parallax => different* = 29
- 30. Findings Tracing speed Tracing failures(fewer) Sketches * (*) sketches selected three times more frequently 30
- 31.
- 32. Implications Case for blunt-tipstylus 32
- 33. IIS-1227639 IIS-1249229 IIS-1253863 Donald W. FeddersenChaired Professorship Purdue School of Mechanical Engineering. Acknowledgment Questions? S. Karthik Badam sbadam@purdue.edu 33
Editor's Notes
- #2 Introduce myself - co-authors – paper about evaluating the tracing and sketching performance on digital tablets
- #3 Need for paper in day-to-day activities – newspapers, novels, and maps – replaced with well-designed tablet applications. [Segway] tablet replacing paper for content consumption. But what about content creation? For example, an industrial design
- #4 Industrial design – requires paper for drafting – content creation – custom hardware for sketching and design [Segway] Provide natural interaction For example, with digital media you no longer need to use a copier to share your ideas, you can just transfer them with a button click. Although such tools exist they cannot promise better adaptability of designers to digital medium. The question we ask is whether you can sketch on a tablet as seamlessly or naturally as on a paper?
- #5 Coming back – Wacom devices direct/in-direct interaction replace paper - but there are also numerous mobile devices – direct-touch – why not use them? [Segway] For one thing, the capacitive touch tablets have finger input
- #6 [Segway] For one thing, the capacitive touch tablets have finger inpu As kids used to finger painting – its messy – but learn how to draw shapes with fingers – still we are more used to pen input
- #7 Luckily, we now have digital styli, that can replace enable pen-like input to tablets – numerous models – differ in tip dimensions, material etc. – we have considered a common representative Wacom Bamboo (best consumer feedback).
- #8 Considering the digital tech -- Designer’s notebook – repository of sketches of ideas – may not be fully mature – represents early-design process – these design notebooks are useful because – small, portable [Segway] considering all the digital technology we have right now, what is stopping us from replacing this?
- #9 A typical early design has multiple steps. Play animation Can we replace pen and paper with digital tools (tablets, styli)? [Segway] aspects – that affect tablets
- #10 We have identified 4 aspects – familiarity – occlusion – friction – parallax [segway] objective of our research – compare the performance of touch tablets with paper – ecological valid study with less constraints – similar attempts in past to compare input devices. Bridging pen-paper and digital
- #11 Accot and Zhai 1999 Zabramski et al. 2011 both handled tracing tasks did a rigorous study with multiple shape tracing [Segway] since we target both sketching and tracing, as in early design, we did two user studies [Need to show roadmap at the end]
- #12 14 participants – students from various departments in Purdue University – all had novice level exposure to design through a toy design course 3 media – 2 tasks – multiple shapes – 5 shapes – 2 shapes. We conducted a user study to understand the performance of three medium + input combinations i.e., stylus + tablet, finger + tablet, and pen + paper for sketching and tracing. Inspired by the previous research work in evaluating various input devices for tracing different shapes using Steering’s law, we have chosen 5 different shapes for tracing and two common 3D shapes for sketching. We recruited 14 participants (13 male + 1 female) from various departments in our University. They were all students and they only had beginner-level experience to early design. In essence, they were not expert designers.
- #13 Tracing tasks – 5 shapes increasing complexity in curvature – participants asked to keep to an error tunnel – 3 times of each medium (so that we can compare pen-paper with tablet) [Mention how the task was done on paper] - video recorded and analyzed
- #14 Tracing speed – faster on tablet with stylus input – followed by finger with tablet – pen-paper – just put in the average values for your reference – significant
- #15 Tracing failures – least on pen-paper – followed by stylus tablet – finger tablet – pen-paper significantly better but finger-tablet had the worst failures
- #16 In the post-survey questionnaire – we asked comfort, confidence, accuracy – pen-paper – stylus 12, 10, 10 – while only most of the participants were not with pen-paper [Segway] this covers the tracing tasks, following this the participants did sketching task
- #17 Sketching tasks – 2 shapes – 3d shapes – 3 times of each medium (so that we can compare pen-paper with tablet) – participants selected the best representative sketch Analysis – instead of using image processing techniques, that are hard to define – used sketch quality measure from crowdsourcing – lineups of sketches – choose one -- ratios In each lineup, 5 sketches from the library of 42 submitted sketches for each shape was randomly displayed in a single row.
- #18 277 respondents – for sketch quality - 5,440 individual responses – and from this *[enter slide]*
- #19 In the post-survey questionnaire – again pen-paper (of course) – but this time stylus 9, 8, 7 and finger were similar except for accuracy – this can be due to the large occlusion [Segway] looking from the aspects perspective
- #20 *Hard to quantify Familiarity to pen-paper > tablet - occlusion is more for finger (tip size) – friction couldnot be quantified but the perception is that more on pen-paper – parallax is more on tablet screen [Segway] clearly the media differ in these aspects but if we look at the results again
- #21 Tablet with stylus and paper performed comparably* [Segway] so far we have looked at using existing generic input styli for direct-touch tablets. – followed with a different study - Blunt vs Sharp-tipped (Samsung note device). Coming to the second part of our paper,
- #22 Now-a-days we have tablets with better styli such as Samsung note – they have a hard tip for handwriting – so we wanted to compare them with the blunt-tipped Wacom bamboo stylus in the follow-up study
- #23 Additional bearing block (no motivation)– Sharp tipped can be used for intricate shapes..
- #24 The tasks were similar to before but this due to the low participant pool we had to do a expert voting for sketch quality rather than crowdsourcing. Three repetitions – one selection - Not using lineups – but pair-wise selections by expert judges.
- #25 Speed was higher!!!! Not much …The results were not significant
- #27 Most of the participants were Comfortable with blunt tipped stylus – because the dimensions match a normal pen (quoted)
- #29 Accuracy, of course, was better for hard-tipped stylus
- #30 *Hard to quantify Looking from aspects the devices clearly were different – occlusion was more on the blunt tip but the questionnaire – doesn’t translate to this – because **tip size is one thing but form factor also matters** Samsung designed a small pen **
- #31 Results not much but summarizing, we are planning to do a more rigorous study in future but
- #32 We can take these results into account to replace the traditional design notebook with digital tools for tablets
- #33 Blunt-tip stylus is not so bad – if we can add features to improve the accuracy – form factor is important – Thank you!! If you disagree with any of the findings here we can have a discussion now or even offline
- #34 More details refer to the paper!