Back to the Tablet Pen vs. mouse The Tablet PC: Designing The - PDF document

Back to the Tablet Pen vs. mouse The Tablet PC: Designing The Tablet PC: Designing Pen- Pen -based Applications based Applications ! The mouse is better ! The pen is better Part II Part II ! Targeting more accurate ! Superior continuous control ! Easy to leave in fixed position ! Natural device ! Integrates well with ! Direct manipulation on buttons screen Richard Anderson ! Cursor positioning is ! Does not require auxiliary (slides based on Rob Jarrett’s slides) accurate surface ! Does not require digitizer ! More info than just x-y Pen as mouse: Targeting Pen as mouse: Clicking ! Clicking with a pen is tough ! Pen motion while hovering ! Legacy applications typically assume during a ! Positioning click the mouse doesn’t move ! Targeting may require pen to be stationary ! Pen taps are more like little strokes or stabs for a period of time because of pen skidding and high-precision ! Pushing buttons cause pen tip to move digitizers ! Surface of tablet may be slippery ! Detecting the difference between tap and a ! Pressing on screen causes pen to move drag is an interesting problem! ! Tablet may not be stationary ! Double-clicking is even tougher ! Quick motion means sloppier result Pen as mouse: Pen as mouse: Pen positioning Targeting guidelines ! Pen positioning can be arduous work if UI ! Cursor feedback requires targeting all over the display ! Mouse can move the cursor far without much ! Bigger, easily-targeted controls arm/hand movement, but the pen requires a lot of ! Generous tap, double-click, and hover arm/hand movement ! Menus and toolbars are typically at the top of a tolerances window; editing often occurs mid-way or toward the bottom ! Keep related objects in proximity ! Lots of physical arm/hand movement results – a real pain for users ! More local UI is desirable (e.g. context menus) 1

Pen as mouse: Right-clicking Digital ink realism ! Ink should look smooth ! Need to be able to right-click with the pen ! No “jaggies” -> antialiased ! While not used by majority of Windows users, ! No straight lines -> curve-fitted still an important capability for backwards ! Use pen pressure information compatibility and contextual UI ! Vary stroke width (more pressure means ! Solutions: “Press-and-hold” and pen barrel- wider stroke) button invocation ! Support pen tips ! P & H was fairly controversial because some felt it ! Round/ballpoint vs. rectangular/ got in the way highlighter Digital ink performance Pen modes & cursors ! Explicit vs. implicit input modes ! Writing requires uninterrupted inking ! A.k.a. Modal vs. modeless ! Users have difficulty with delays in ink ! How to allow things to be efficient but not appearance confuse users ! Users are frustrated with delays in inking ! Select mode uses “right-mouse button” for ! Guideline implicit mode as well as utilizing an explicit ! Ensure fast efficacy mode ! Is it as fast as writing on paper? ! Erase mode uses pen’s eraser tip (if available) for implicit mode as well as utilizing an explicit mode Pen modes & cursors Gestures ! Need feedback as to the mode of the ! Commands delivered with key strokes pen ! Examples ! Indicates actions available to the user ! Scratch out ! Guideline ! Keyboard ! Develop a set of cursor feedback to indicate ! Question the different modes of the pen ! Next page ! Careful attention to cursor design ! Previous page ! Either symmetric or use handedness setting 2

Pen gestures Writing location ! Gestures need precise tuning ! Users have an initial expectation that they ! Trade-off between accidental activation vs. not can write digital ink anywhere getting when wanted ! Guideline ! False activations are annoying and distracting to the task! ! Communicate clearly where users can ink ! Guideline ! Ink enabled controls should be self-evident ! Use gestures guardedly ! Error on the side of having “zero” incidence of false activation ! Non-destructive consequences are better Ink selection Recognition expectations ! Handwriting recognition is highly variable ! Traditional rectangular selection tools are by person inadequate ! Errors are expected ! “Lasso” selection is much more natural ! Perceived good or bad handwriting effects ! Percentage-based stroke tolerances expectation of accuracy ! Employ word-based selection ! Guideline ! Visual feedback is essential, real-time is much ! Be realistic about recognition accuracy rate, better than static don’t rely heavily on it for authoring Text input My observations of TPC use ! Freecell / spider work great ! Direct writing with reco ! Text input area with reco ! Minesweeper fails (difficulty of right ! Writing buffer, text buffer, application click for marking bombs) ! Special forms of input ! Inkball is okay ! Stylized letters ! Very satisfied with airplane and meeting ! Gestures (quikwriting) use ! Stylus controlled keyboard ! Connect a real keyboard 3

Observations (cont.) Observations (cont.) ! I make extensive use of journal ! Handwriting reco is adequate for text input for short, sentence based input ! See CSE 490ra Winter website for example of Journal notes ! Powerpoint slides ! Useful as a brainstorming / note taking tool ! Answering email ! I have never converted Journal Notes to ! Painful for forms entry and longer text, other than for demo purposes documents ! I make frequent misspellings in journal (more than on paper?) ! Hard to enter text outside of dictionary ! Rely on scratch out gesture, not eraser Observations (cont.) Key Frame Animation ! Journal ! Given two ink figures, construct a ! Lasso for selection works well continuous transformation from one to ! Color/pen selection could be improved the other ! Scroll bar is problematic – on HP, I use the page toggle on side ! Office Tablet PC Pack controls are not very good ! Pen selection in PPT Visualization steering Natural UI for Work list ! Given a large diagram, how do you ! Keep track of set of tasks control a visualization ! Support control of tasks, annotation, ! Static manipulation on multiple scales import / export ! Time series visualization ! Service technicians application ! Strict pen manipulation ! Possible approaches ! Domain elevators ! Develop natural metaphor – piles of cards? ! Large buildings (Sears towers) ! Direct manipulation interface ! Time series visualization ! Pen based NL / diagram interface 4