RESNA 28th Annual Conference - Atlanta, Georgia
Denis Anson, MS, OTR, Penni Moist, OTS, Mary Przywara, OTS, Heather Wells, OTS, Heather Saylor, OTS, Hantz Maxime, OTS,
College Misericordia, Dallas, PA
Word prediction is often recommended by therapists as a means to improve typing speed for clients with physical limitations. While literature suggests that word prediction does have an effect on writing proficiency, increased speed is not one of its benefits when used with a standard keyboard. One reason given for the failure of word prediction to accelerate typing is that the user must look away from any source document to scan the prediction list during typing. The focus of this research was to determine whether word completion or word prediction programs would increase typing speed when used with an input method (on-screen keyboard) that also requires looking away from the source document. Overall, these results show that the use of word prediction and word completion may assist on-screen keyboard users to improve typing speed.
Key Words: on-screen keyboard, word prediction, word completion, typing speed, assistive technology.
An able-bodied person commonly accesses the computer through the keyboard and mouse. When a person acquires a disability, the keyboard and mouse may cease to be tools that promote access and become barriers to participation. Finding alternative means for people with physical disabilities to access a computer system is imperative in assisting them to obtain information, perform work and school tasks, and communicate with others.
For individuals who have difficulty using a standard keyboard effectively, but can use a mouse emulator, an on-screen keyboard is an access method that is easily learned, draws on prior experience, and allows reasonable levels of productivity. While an on-screen keyboard makes typing possible, it does not allow a person to type quickly. To minimize the effect of single-digit typing and decreased motor control, some means of accelerating typing is needed.
One approach that may improve typing speed for users of on-screen keyboards is to incorporate word completion or word prediction. Word completion and word prediction were originally developed for individuals with physical disabilities to decrease the number of keystrokes required to type words and sentences (1). Word completion provides the user with one or more predictive suggestions after the user has typed the initial letters of a word (2). Word prediction is a feature that, after a selection has been made for the current word, attempts to predict the next word in the sentence. Word prediction has been noted to reduce the number of keystrokes by up to half (3, 4, 5). This reduction of keystrokes while using word prediction could allow the typist with limited endurance to accomplish more work with the limited energy available for task completion.
The focus of this research is to determine whether word completion or word prediction programs will increase typing speed when used with an input method (on-screen keyboard) that also requires looking away from the source document. We hypothesize that the addition of word completion to an on-screen keyboard will enhance typing performance as compared with the use of an on-screen keyboard without word completion. Since word prediction requires even fewer keystrokes, we hypothesize that the addition of this feature will improve typing speeds over both the on-screen keyboard alone and the on-screen keyboard with word completion.
This study used a single-subject, successive intervention design to test typing speed and accuracy using an on-screen keyboard with integrated word prediction software. The goal of this study was to determine whether word completion and word prediction helps or hinders the typing process when used in conjunction with the on-screen keyboard. To make this analysis, the participants were tested using each of the following options: on-screen keyboard only, on-screen keyboard with word completion, and on-screen keyboard with word prediction.
Ten able-bodied people, five males and five females, with ages from 20 to 38, participated in this study. Each of the participants had vision adequate to read a document printed in 12 point, Times New Roman font, was able to read and speak English fluently, and was able to sit unsupported for more than 30 minutes at a time in an armless chair.
Equipment/Measurement tools. Each participant used a single computer for all typing trials. All text was entered into one of five Windows-based, standard laptop computers..
All text entry was performed using ScreenDoors 2000 and a Microsoft compatible mouse. The size of the keyboard was standardized using a paper template. The word-prediction tool bar was positioned horizontally at the top of the onscreen keyboard. (The word-prediction window was not included inside the template space.)
Source Document. Participants were asked to type test segments from A Case of Identity, by Sir Arthur Conan Doyle. The entire novel was imported into Screendoors’ dictionary in order to familiarize the system with commonly used words and word patterns of the text.
Procedure. This study used the protocol proposed by Anson, et. al.(6).
|
Words Per Minute |
Percent Error |
||||
|---|---|---|---|---|---|---|
Participant Number |
No Word Prediction |
Word Completion |
Word Prediction |
No Word Prediction |
Word Completion |
Word Prediction |
1 |
9.6 |
9.5 |
10.5 |
2.4 |
1.6 |
1.1 |
2 |
9.2 |
10.7 |
11.1 |
4.5 |
2.9 |
2.7 |
3 |
9.3 |
10.1 |
10.3 |
1.6 |
1.1 |
.8 |
4 |
8.9 |
9.3 |
9.0 |
.9 |
.5 |
1.3 |
5 |
12.0 |
10.5 |
10.7 |
.3 |
.5 |
.3 |
6 |
9.1 |
8.8 |
9.8 |
.6 |
.6 |
.7 |
7 |
9.3 |
9.7 |
10.1 |
1.1 |
1.9 |
1.5 |
8 |
11.9 |
12.5 |
11.0 |
1.4 |
.9 |
1.4 |
9 |
6.9 |
7.3 |
7.9 |
3.4 |
.7 |
1.5 |
10 |
6.8 |
9.5 |
9.9 |
.5 |
.7 |
1.7 |
As shown in Table 1, seven out of the ten participants had the highest typing speed for word prediction. Five out of these seven people had the second highest typing speed using word completion and the lowest speed while typing using no word prediction (See Table 1). Two out of the seven had the second highest typing speed using no word prediction and the slowest speed when using word completion (See Table 1). Word completion was also faster than the on-screen keyboard alone in seven out of the ten participants. Five of these participants had their highest speed with word prediction followed by word completion and no word prediction. Two participants had their fastest speed with word completion, followed by word prediction. No systematic differences in error rate were identified between the methods. Although the majority of the participants had the fastest speed using word prediction, most of these participants felt that using word prediction was the most frustrating of the three methods of access used in the research process. Nine out of the ten participants stated that they disliked looking away from the document to search the list because they lost their place on the copy. Eight out of the ten felt that searching through the word list was tedious and distracting.
Historically, word prediction and word completion programs have been shown not to improve typing speed when used with a standard keyboard. In this study, most participants were able to type faster using word prediction as compared with both word completion and the on-screen keyboard alone. Most typists were able to type faster using word completion than with the on-screen keyboard alone. Thus, the use of word completion and word prediction to improve productivity for the users of on-screen keyboard users is supported by this study.
The focus of this research was to determine whether word completion or word prediction programs would increase typing speed when used with the on-screen keyboard. The results show that the addition of word completion to the on-screen keyboard increased typing speed for the majority of the participants in this study. Since word prediction requires even fewer keystrokes than word completion, we hypothesized this feature would improve typing speeds over both the on-screen keyboard alone and the on-screen keyboard with word completion. This hypothesis was also substantiated.
Denis Anson, MS, OTR
Director of Research and Development
Assistive Technology Research Institute
College Misericordia
Dallas, PA 18612
(570) 674-6413
danson@misericorida.edu