Project Report An investigation on data entry effectiveness & efficiency

Agenda  Introduction  Experiment Design  Experiment Platform  Data Analysis  Conclusion

Introduction  Developing fast and efficient means for text entry is one of the most pressing research topics in today!  Although the QWERTY layout is entrenched for physical keyboards, soft keyboards are easy to implement and customize.

Objective  To develop a statistically reliable analysis of possible factors that may have influence on the input efficiency and error rate of the soft keyboard and give design guideline on this issue.

Response variables  Average typing speed  Error rate

Cause–and-effect Diagram

Control variables  Keyboard layout  Key size  Key shape  Mouse C/R ratio

Keyboard layout

Other Control Factors Key size Large : the size of keys on standard physical keyboard Small : that of general electronic dictionaries Mouse C/R ratio High : the highest in the tested computer. Low : adjusted one which is the lower bound that one can bear Key shape  There are three kinds of key shape generally, but we choose two of them for simplicity: circle and square, the rest is hexagon

Learning Curve for Novice

Experiment Design(1/3)  Mixed Level Full Factorial Design  Repleicated on two testees  Each testee enters the same paragraph of text with different combinations of control factors

Experiment Design(2/3)

Experiment Design(3/3)  Block On Noise Variables  Data within each block is homogenous (exclude the potential influence of different users)  Enough DOF to Estimate Interactions  Eliminate Learning Effect  Two replicates with different (randomly generated) execution sequence

Platform(1/4)  Large-Small  High-Low  FITALY-OPTI II- METROPOLIS-QWERTY  Square-Circle.  There are 16 different types of soft keyboard in all.

Platform(2/4) FITALYOPTI II METROPOLISQWERTY

Platform(3/4)

Platform(4/4)  Saved in CSV files  Key name, x- coordinate, y- coordinate, the time when it is entered  Errors: number of “Backspace”

Discussion on Error Rate  Errors may not be noticed immediately.  Sequence of the words or letters may be changed, due to other reasons unrelated to the keyboard. Click “Backspace” when ever testee notices error and count the number of “Backspace” clicked as error

Analysis  Tools  DOE++  Minitab  Two Kinds of Responses  Time  Error rate  Principle  Treat different responses separately  Find an integrative optimal solution

Response Time Data Analysis

Step 1: ANOVA The main effect is significant

Step 2: Regression  Ignore the 3 or higher order effects  Keep the significant items

Step 3:Probability Plot

Step 4: Eliminate Insignificant factors  Keep A, B1, B2, B3

Step 5: Residual Checking

Step 6: Interaction Matrix

Conclusion  Time will be shorter when  factor size= 2(larger size)  factor layout=1(qwerty), and then 4(FITALY), 2(metro), 3(OPTI)  The factor shape and C/R ratio will not influence the result if the response is time

Error Rate Data Analysis

Step 1: ANOVA The main effect is significant

Step 2: Regression  Ignore the 3 or higher order effects  Keep the significant items

Step 3: Probability Plot

Step 4: Eliminate Insignificant Factors  Keep B 1, AB 1, AB 2, C

Step 5: Residual Checking

Step 6: Interaction Matrix

Conclusion  It is more reasonable to choose factor size= 2(larger size)  Hence factor layout = 4(FITALY) will be chosen when the size=2  The factor C/R ratio=1(low) will be better  Factor shape has no effects

Final Recommendation  Larger size  FITALY layout  Low C/R ratio  Both shapes

Potential Weakness  Limited Sample Size  Both Young Female University Students  Familiar with QWERTY  Without Upper Case  Limited to English Text

Q&A