Presentation is loading. Please wait.

Presentation is loading. Please wait.

The Keyboard Study Lecture /slide deck produced by Saul Greenberg, University of Calgary, Canada Notice: some material in this deck is used from other.

Similar presentations


Presentation on theme: "The Keyboard Study Lecture /slide deck produced by Saul Greenberg, University of Calgary, Canada Notice: some material in this deck is used from other."— Presentation transcript:

1 The Keyboard Study Lecture /slide deck produced by Saul Greenberg, University of Calgary, Canada Notice: some material in this deck is used from other sources without permission. Credit to the original source is given if it is known, image soruce:

2 The Context Company produces kiosks. walk-up and use situations only mouse input typically for navigating(e.g., menus) but on screen keyboard for occasional text input end-customers vary in typing ability; text entry must be quick to avoid line-ups errors costly (e.g., banking) small displays preferred due to cost, but…

3 The Idea Qwerty vs Alphabetic, two sizes possible

4 The problem Which is best? What is the worst case?

5 Null Hypothesis 1 There is no difference between people's mouse-typing ability as measured in speed (characters per second) and error rate (ratio of extra characters typed over the minimum required) when using a qwerty, alphabetic, or random layouts on a simulated keyboard that is small (measured as …) vs. large (measured as …).

6 Experimental Design (ANOVA) Type QwertyAlphabeticRandom SizeSmallS 1 ( c hars/sec) S 2 ( c hars/sec) … S n ( c hars/sec) same Largesame Dependent variable: Characters/sec

7 Experimental Design (ANOVA) Type QwertyAlphabeticRandom SizeSmallS 1 ( errors ) S 2 ( errors ) … S n ( errors) same Largesame Dependent variable: Errors (extra characters)

8 Null Hypothesis 2 People's typing speeds measured in characters per second when touch-typing vs. mouse-typing is not correlated on the 3 keyboards or their size

9 Experimental Design (Regression) Mouse typing speed QwertyAlphabeticRandom SmallLargeSmallLargeSmallLarge Physical Typing speed S 1 (t 1,t 2) S 2 (t 1,t 2) … S n (t 1,t 2) same

10 Issues ? Design Subject selection Task Ethics Controls Data collection / analysis

11 Issues ? Design random keyboard not really random layout may affect results (guard zones, key size?) Subject selection range of expertise not random generalization Task copy typing vs. free form typing was there sufficient practice, particularly with non-familiar keyboards? (realism) learning curve (sentences same across all conditions) sentence length (does it match real task?) sentence type (punctuation, capitals, etc.) fatigue, boredom motivation to type

12 Issues ? Ethics violations no approval power situation – had to be a subject Controls varying computers / screens / sound output varying size of displays thus keyboard size environmental conditions: rooms, furniture, computer placement Data collection / analysis extra step in moving data to spreadsheet error prone, tedious errors – is this the best way to record it? unclear when to discard data (e.g., above a certain error rate?) unclear if errors due to keyboard (typing) or mis-reading / skipping words in sentence

13 BUT Many issues randomized across all conditions Large effects may still emerge Interpretation critical generalization applicability to the problem revisit the scenario In spite of problems, valuable as evidence as interpreted by you

14 You know now Designing even a simple study requires intense planning and preparation in-depth thinking of all aspects pilots to debug problems understanding limits interpreting results as evidence for / against the problem olimitations, implications, generalization, applicability, etc

15 Permissions You are free: to Share — to copy, distribute and transmit the work to Remix — to adapt the work Under the following conditions: Attribution — You must attribute the work in the manner specified by the author (but not in any way that suggests that they endorse you or your use of the work) by citing: “Lecture materials by Saul Greenberg, University of Calgary, AB, Canada. Noncommercial — You may not use this work for commercial purposes, except to assist one’s own teaching and training within commercial organizations. Share Alike — If you alter, transform, or build upon this work, you may distribute the resulting work only under the same or similar license to this one. With the understanding that: Not all material have transferable rights — materials from other sources which are included here are cited Waiver — Any of the above conditions can be waived if you get permission from the copyright holder. Public Domain — Where the work or any of its elements is in the public domain under applicable law, that status is in no way affected by the license. Other Rights — In no way are any of the following rights affected by the license: Your fair dealing or fair use rights, or other applicable copyright exceptions and limitations; The author's moral rights; Rights other persons may have either in the work itself or in how the work is used, such as publicity or privacy rights. Notice — For any reuse or distribution, you must make clear to others the license terms of this work. The best way to do this is with a link to this web page.


Download ppt "The Keyboard Study Lecture /slide deck produced by Saul Greenberg, University of Calgary, Canada Notice: some material in this deck is used from other."

Similar presentations


Ads by Google