Assistive Technology for Postsecondary Students with Disabilities: Researching Text-to-Speech Software

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1 Assistive Technology for Postsecondary Students with Disabilities: Researching Text-to-Speech Software Maureen G. Hewlett, University of Northern British Columbia, Canada A. Nicole Burnett, University of Calgary, Canada Brenda J. Christensen, University of Northern British Columbia, Canada William J. Owen, University of Northern British Columbia, Canada Abstract: Postsecondary students with learning disabilities (LD) who experience difficulties accessing printed material are often prescribed text-to-speech (TTS) screen reading technology. Researchers compared performance on the Nelson Denny vocabulary and reading comprehension tests by postsecondary students in both TTS aided and unaided natural reading conditions. Participants included students diagnosed with LD, students with English as their second language (ESL) and proficient readers. Results showed that the students with LD did not perform significantly better with the aid of TTS and that the ESL and proficient reading groups experienced TTS-related interference. Keywords: Learning Disabilities, Screen Readers, Text-to-Speech (TTS), Reading Performance The number of students with learning disabilities (LD) attending postsecondary institutions in Canada and the United States has increased significantly (Fichten et al., 2001; Thomas, 2000) and these student often require academic accommodation to be successful (Blackorby & Wagner, 1996; Murray, Goldstein, Nourse, & Edgar, 2000). The use of assistive technology to help students overcome disability-related barriers is of great interest to disability service providers because they are responsible for implementing supports, accommodations and special needs programs (Higgins & Raskind, 1997; Mull & Sitlington, 2003). Assistive technologies marketed for use by students with LD support skills in written language, reading, spelling, organization and memory because those skills are the most demanding in the academic setting. Utilization of the technology is intended to compensate for specific cognitive deficits related to the disability (Fichten et al., 2001; Higgins & Raskind, 1997; Mull & Sitlington, 2003). However, students often abandon their assistive technology, which raises the question of whether it is helping or creating more work for the user (Roessler & Kirk, 1998). Text-to-speech (TTS) is an assistive technology that is recommended for use by postsecondary students with LD (Fichten et al., 2001; Mull & Sitlington, 2003). With this technology the user views printed material on a computer screen and the text is spoken aloud. For example, both texthelp and Kurzweil 3000 assistive software programs read electronic text by word, phrase, paragraph, or selected text. The synthetic voices generated by the software can be adjusted to suit individual requirements by altering the pitch, speed, volume and word pause. The to be read material can be highlighted as it is spoken providing audio-visual reinforcement, which is intended to increase word recognition.

2 The extant literature on the compensatory effectiveness of TTS is sparse, participants vary in age and reading abilities, methodologies lack consistency and results are mixed. For example, several researchers reported that the use of TTS tended to elevate the reading comprehension scores of less proficient readers and depress the performance of more proficient readers (Elkind, 1998; Elkind, Cohen, & Murray, 1993; Higgins & Raskind, 1997; Montali & Lewandowski, 1996). Conversely, Brown and Augustine (2000) found no significant difference between students performance using TTS versus paper and pencil formats when reading ability was controlled. While there is some evidence that TTS benefits poor readers, there is little empirical research conducted on the use of TTS with postsecondary students who have been diagnosed with a LD (Higgins & Raskind). The present research focused on the compensatory effectiveness of texthelp Read & Write Gold (v ) TTS technology with postsecondary students. Participants included students who had been formally diagnosed with LD, those who had English as their second language (ESL), and proficient readers. It was thought that if TTS assists with reading comprehension for students with LD, it should also assist ESL students. The inclusion of the ESL group extends research conducted by Leong (1999) who found that postsecondary students with LD read at the same efficiency level as their ESL counterparts. In his research, Leong used a reading level control group that was comprised of ESL students and a chronological age control group that consisted of proficient readers. The hypothesis of the present study was that TTS would provide cognitive compensation for students with LD and ESL. The authors predicted that the LD and ESL participants would have improved vocabulary and reading comprehension scores when using TTS compared to their scores without its use. Research Methods The study was approved by the University of Northern British Columbia s (UNBC) research ethics committee and participants provided informed consent. Participants were recruited using on-campus posters and announcements in first year psychology classes. A trained research assistant conducted testing on two separate days, about two weeks apart. After completing the final testing session the participants were informed that the research was designed to investigate whether scores differed on the vocabulary and reading comprehension tests administered in each of the experimental conditions. Four of the 48 participants who began the project did not attend the second testing session so their data was removed from the final analyses (N = 44). Group 1 consisted of 8 students who were formally diagnosed with a LD and who were receiving academic accommodation for their disability. The LD group included 3 females and 5 males who ranged in age from 20 to 36 yearsold (M = 26.4, SD = 5.8). Group 2 consisted of 13 ESL participants (12 females and 1 male) who ranged in age from 19 to 44 years-old (M = 30.4, SD = 8.4). Group 3, the proficient readers, consisted of 15 females and 8 males who ranged in age from 19 to 51 years-old (M = 25.5, SD = 7.2). All participants completed the vocabulary and reading comprehension sections contained in the

3 equivalent forms (G and H) of the Nelson Denny Reading Test (Brown, Fishco, & Hanna, 1993) on the computer. Forms G and H of the test and reading conditions were presented in counterbalanced order: In the unaided condition participants read naturally without the aid of the TTS software and in the aided condition they used texthelp assistive software. The testing sessions were conducted individually in a laboratory to avoid potential distractions and no time limits were imposed, participants were asked to complete all of the test items to the best of their ability. Each participant s natural reading speed in words per minute was obtained in the unaided reading comprehension session. The default texthelp settings were held consistent for all aided testing sessions. These defaults included a reading speed of 169 words per minute, the normal female voice and use of text highlighting. Results Presentation order effect. Oneway analysis of variance (ANOVA) was conducted to determine whether the order in which the Nelson Denny was presented to the participants might have had an effect. The results showed that presentation order, form G or H with or without the aid of texthelp, did not influence the results, F(1, 42), ps >.07). Reading Speed. ANOVA on the mean number of words read per minute showed that there was a significant difference in the natural reading speeds among the groups, F(2, 41) = 10.2, p <.01). Posthoc analyses using the Fisher s least significant difference (LSD) found that the reading speed between the LD and ESL groups was not significantly different (M = 155.1, SD = 69.4 and M = 137.5, SD = 32.4, respectively). The difference between the means for those groups was 17.6 (SEM = 20.6, p =.4). However, both the LD and ESL groups read significantly slower than the proficient readers (M = 205.5, SD = 42.4). The differences between the mean for proficient reading group and the means for the LD and ESL groups were 50.4 (SEM = 18.8, p =.01) and 68.1 (SEM = 15.9, p <.01), respectively. Further analysis on reading speed was conducted to determine whether there were differences between the participants natural reading speed in words per minute and the default reading speed of 169 words per minute set in texthelp. The one sample t-tests showed that the ESL group read significantly slower (137.5, SD = 32.4) than 169 words per minute, t(12) = 3.5, p <.01. The proficient readers read significantly faster (M = 205.5, SD = 42.4) than the texthelp default setting of 169 words per minute, t(12) = 4.1, p <.01, and there was no significant difference between the LD group s natural reading speed (M = 155.1, SD = 69.4) and the default setting in texthelp, t(7) =.6, p =.6. Vocabulary. ANOVA results on the mean number of correct vocabulary responses showed that there were significant differences in the vocabulary scores between the groups in both the unaided and aided conditions, F(2, 41) = 22.3 and F(2, 41) = 23.2, p <.01, respectively. The mean vocabulary scores for the groups in the unaided and aided conditions are displayed in figure 1.

4 Nelson Denny Vocabulary Mean Number of Correct Responses LD ESL Proficient Group Unaided TTS Aided Figure 1. Group mean scores in the aided and unaided vocabulary test conditions. Multiple comparisons among the groups were made using Fisher s LSD. Those posthoc tests revealed that in the unaided condition, the proficient reading group (M = 64.8, SD = 7.8) performed significantly better than both the LD (M = 55.8, SD = 13.9) and ESL (M = 41.8, SD = 10.5) groups. The difference between the mean for the proficient reading group and the means for the LD and ESL groups were 9.0 (SEM = 4.1, p <.05) and 23.0 (SEM = 3.4, p <.01), respectively. The results also showed that with no aid, the LD group performed significantly better on the vocabulary test than the ESL group. The difference between the means for those groups was 14.0 (SEM = 4.5, p <.01). In the aided condition using texthelp, the difference on vocabulary performance between the proficient readers (M = 64.5, SD = 9.1) and the students with LD (M = 63.4, SD = 7.0) was not significant. The differences between the means for those groups was 1.1 (SEM = 3.9, p =.8). However, both the proficient readers and the LD group performed significantly better on the vocabulary test in the aided condition than the ESL group (M = 43.0, SD = 11.1). The differences between the mean for the ESL group and the means for the proficient readers and the LD group were 21.5 (SEM = 3.3, p <.01) and 20.4 (SEM = 4.2, p <.01), respectively. Paired sample t-tests were used to examine the within group differences in vocabulary performance between the unaided and aided conditions. None of the groups showed significant differences in the number of correct vocabulary responses obtained in the two experimental conditions, all ps >.05 (one tailed). Reading Comprehension. ANOVA results on the Nelson Denny reading comprehension scores showed that there were significant differences between the groups in both the unaided and aided reading conditions, F (2, 41) = 4.7, p <.05 and F(2, 41) = 5.4, p <.01, respectively. The mean comprehension scores for the groups in the two experimental conditions are displayed in figure 2

5 Nelson Denny Comprehension Mean Number of Correct Responses LD ESL Proficient Group Unaided TTS Aided Figure 2. Group mean scores in the aided and unaided reading comprehension test conditions. When reading comprehension scores were compared for the unaided condition, the LSD posthoc analyses showed that the proficient reading group (M = 29.7, SD = 3.1) performed significantly better than both the LD (M = 26.0, SD = 6.0) and the ESL (M = 26.1, SD = 3.7) groups. The differences between the means for the proficient reading group and the LD and ESL groups were 3.7 (SEM = 1.6, p <.05) and 3.6 (SEM = 1.4, p <.05), respectively. However, the difference in reading comprehension performance between the LD and the ESL groups in the unaided condition was not significant. The difference between the means for those groups was.1 (SEM = 1.8, p =.97). The analyses showed that in the aided condition, there was no significant difference between the reading comprehension scores obtained by the proficient readers (M = 28.0, SD = 4.3) and the LD group (M = 28.0, SD = 5.0). The difference between the means for those groups was.04 (SEM = 1.9, p =.98). However, significant differences in comprehension performance were found between the ESL group (M = 23.1, SD = 4.7) and both the proficient readers and the LD students. The differences in the means between the ESL group and the proficient reading and LD groups was 4.9 in both cases (SEM = 1.6, p <.01 and SEM = 2.0, p < 05, respectively). The paired sample t-tests revealed that the ESL and the proficient reading groups showed a significant difference in comprehension performance between the aided and unaided conditions. For the ESL students, performance on reading comprehension with the aid of texthelp (M = 23.1, SD = 4.7) was significantly poorer than without the aid of TTS (M = 26.1, SD = 3.7), t(12) = 2.6, p =.02 (one tailed). The results also showed that the proficient readers performance on comprehension was significantly lower in the aided reading condition (M = 28.0, SD = 4.3) then in the unaided condition (M = 29.7, SD = 3.1), t(12) = 1.9, p =.04 (one tailed). The paired sample t-test between the aided and unaided reading comprehension conditions for the LD group was not significant, t(7) =.8, p =.22 (one tailed).

6 Limitations The results reported here must be interpreted with caution because of the limitations within the study; most notably the small and unequal sample sizes. It was difficult to recruit participants from the relatively small LD and ESL student populations on the UNBC campus. Attrition from those groups was also a problem because some of the participants did not complete the study. Nevertheless, the results obtained do provide valuable information and they certainly point to the need for further research in this area. Discussion As expected, the proficient readers read significantly more words per minute than either the LD or ESL participants. Interestingly, the reading speeds of the LD and ESL groups were not significantly different, which lends support to Leong s (1999) contention that those two groups are equally efficient at reading. However, as discussed in the following sections, performance differences between students with LD and ESL were observed in specific areas of the Nelson Denny. When reading was aided with TTS software, the students with LD performed as well as the proficient readers in both the vocabulary and reading comprehension tests of the Nelson Denny. However, the ESL students performance was significantly poorer than either the LD or proficient readers in both vocabulary and reading comprehension in the aided conditions. These results suggest that the ESL students had less vocabulary knowledge and were not as efficient at comprehending information contained in the reading passages as the students with LD. However, when the Nelson Denny was completed without the aid of the TTS, the LD group continued to outperform the ESL group in vocabulary but there was no significant difference in reading comprehension between those two groups. Taken together, the results show that without the aid of TTS, reading efficiency among the LD and ESL students was comparable, thus supporting Leong (1999). However, the current research found that overall; the ESL students had much weaker vocabulary skills than their LD counterparts. Comparisons between the performance of the proficient readers and the students with LD in the aided and unaided conditions reveal interesting trends. With the aid of TTS, the proficient readers and students with LD performed equally well in both the vocabulary and reading comprehension tests. However, when those participants undertook the same tasks unaided, the proficient readers out performed the students with LD in both vocabulary and reading comprehension. Although no significant within group differences were found between performance on the tasks with and without aid for the LD participants, their scores were higher in the aided conditions suggesting they received at least some benefit from the use of TTS. As revealed in the within group analysis, the ESL students and the proficient readers performance in comprehension was significantly lower when they used TTS than when they read unaided. The ESL students unaided reading speed was significantly slower than the pace of reading provided with texthelp, which suggests that the TTS output interfered with their ability

7 to understand the information in the reading passages. The TTS pace of 169 words per minute was likely too fast for the ESL students and thus, resulted in depressed comprehension scores. A similar effect was observed for the proficient readers; their comprehension scores in the aided reading condition were depressed relative to their scores without the use of texthelp. However, in this instance TTS interference may have resulted because the proficient readers natural reading speed was significantly faster than the pace set by the software. Conclusion The results of the present study did not support the hypothesis that using TTS would provide cognitive compensation for students with LD and ESL. Those students did not obtain the predicted improvement in their vocabulary and reading comprehension scores with the use of the technology. For the students with LD, the observed gains in performance when using TTS could at best be considered marginal because those gains were not statistically significant. Furthermore, the results suggest that for the ESL and proficient readers, TTS output interfered with comprehension of the reading passages and thus, had a negative impact on their ability to understand the material. At a practical level, the results of this research underscore the need for disability service providers to train, support, evaluate and monitor each student s experience with TTS technology. Abandonment of TTS could occur, for example, if the reading process is only marginally improved and the student perceives the time and effort required to obtain reading materials in electronic formats, relative to purchasing a printed textbook, are too high. It seems plausible that significant returns in terms of reading time and comprehension of to be learned material would reinforce the benefits of using TTS. Future Directions Determining the specific human and technological factors under which reading is enhanced or depressed is a fruitful area for further research. For instance, a future direction for this line of research would be to investigate the interaction between TTS technology and cognitive processing in word recognition. References Blackorby, J., & Wagner, W. (1996). Longitudinal postschool outcomes of youth with disabilities: Findings from the National Longitudinal Transition Study. Exceptional Children, 62, Brown, J. I., Fishco, V. V., & Hanna, G. (1993). Nelson-Denny Reading Test. Itasca, IL: Riverside. Brown, P. J., & Augustine, A. (2000). Findings of the screen reading field test. Delaware Education Research and Development Center: University of Delaware, Newark, DE.

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