Optimizing the KeyboardPSY/ORF 322 Final Project

Jessica Blankshain, James Ma, and Robert J. Moore

Purpose• Develop a keyboard optimization

algorithm.

– Utilize Fitts’s Law and other aspects of the Card-Moran-Newell (CMN) model of the human processor.

• Demonstrate that neither the QWERTY nor the Dvorak keyboard layout is an optimal configuration of the keys on the three-row keyboard.

– These layouts can be improved upon using quantitative methods.

History: QWERTY

• Old typewriters used typebars and had an “invisible” printing point, leading to frequent jams.

• There is speculation that they intentionally placed all the letters of the word “typewriter” in the top row for quick and easy demonstration.

History: Dvorak

• In the 1930’s, August Dvorak and William Dealey developed and patented a new layout, known as the Dvorak Simplified Keyboard (DSK).

• Designed to improve typing efficiency and user comfort.

• Reasoning for layout was strictly qualitative.

Methods: Scale Issues

Why Not Examine Every Possible Permutation?

At one keyboard per second, that’s 8.41*1024 years.

The sun will burn out after 5*109 of them.

3210*65.2!303030 P

Methods: Keyboard Population

• Rather than look at entire keyboards, examine the influence of specific keys in specific locations.

• There are only 30*30 = 900 key-position pairs.

• We can randomly populate a large number of keyboards, then see how certain keys in certain positions influence their performance.

Methods: Scoring Keyboards

• First, need a figure of merit for keyboard performance:– Compile a large text file

and calculate how long it would take an average human to type that entire file using that keyboard.

– These figures are derived from the CMN model and Fitts’s Law.

Methods: Applying CMN

• Used Fitts’s Law to determine how long it would take a typist to move a finger from one key to another.

• Determined inter-row and inter-finger transition times.

• From this data, could determine the time to transition from any finger in any position to any other.

• See paper for quantitative details.

Methods: Compiling a Text Sample

• ~500KB of raw text

• 80,720 Characters

• Sources:– Popular Novels– Famous Speeches– TV Transcripts– Rap Lyrics

Methods: Algorithmic Flow

• Simulate 90,000 keyboards.• Expect to see each key-

position combination 3,000 times.

• Enough data to determine the best possible key-position combination.

• “Lock-In” that key.• Repeat, simulating only the

remaining 29 keys.• Continue until entire

keyboard populated.

Results

• Outperformed QWERTY by 33.3%.

• Outperformed Dvorak by 6.2%.

Conclusions

• Our method was successful.• While DSK is a quantifiable

improvement over QWERTY, our model is more efficient than both.

• Extensions: Software’s robustness allows for keyboards customized to users or industries.

Naming

MNT RSH = Mt. Rushmore