**7. Results**

**Figure 4.** Selecting target picture from a group of pictures

222 Autism Spectrum Disorder - Recent Advances

**Figure 5.** Introducing verb cards

The study aimed to determine the efficacy of PECS based AAC intervention on development of functional language abilities of children with autism. The children under PECS condition showed quantitative change in their social interactions. A comparison of their composite mean score on FLAS at baseline with that at post intervention showed a significant difference (refer to table 2). As the selection of the children was random, the data was analysed using t-test.


**Table 2.** Comparison of pre and post-test composite mean scores of experimental group on FLAS

The effect of PECS intervention was evident to people who interacted with the children in the experimental group. They noted the difference in the children's ability to communicate meaningfully. Statistical analysis of data supported this observation. The average score at baseline (346.66) showed a significant increase post intervention (512.26). Each of the 15 children in the experimental group benefitted by the intervention. This led to the large difference between pre and post mean scores. The positive effect of training on the children is clear when their pre and post-test individual scores are compared (Figure 7).

As may be seen from Figure 7 that all children gained from the intervention, though some gained more than others. This may be understood in terms of the initial differences that existed among the children due to factors such as age and intellectual levels.

Functional language skills were measured through receptive and expressive language on FLAS. The mean scores on these component skills were compared. The baseline average score on receptive language (224.2) was significantly lower than that at post intervention (329.53) as indicated by the derived t-value (7.05; p<.001). From figure 8 it is evident that all children improved their performance from pre to post test. However, in comparison with others the observed gain was not as much in two of the children.

With respect to expressive language skills, the children's base line mean score on FLAS was 121.8. After 15 sessions of intervention their performance was observed to have improved. They had learned to use picture or symbols to convey their wishes and desires. They were able to engage in more meaningful social interaction. This was also supported by their post-test performance. The average score on FLAS (182.73) was significantly higher as indicated by the derived t-value (6.01, p<.001). This suggested the positive effect of PECS on communication ability. Figure 9 presents the details of pre and post-test individual performance on expressive language skill post intervention.

While the experimental group children received PECS based intervention, those in the control group continued with the intervention provided by their respective schools. At the end of intervention period all children were reassessed on FLAS. The second objective of the study

difference between pre and post mean scores. The positive effect of training on the children is

As may be seen from Figure 7 that all children gained from the intervention, though some gained more than others. This may be understood in terms of the initial differences that existed

Functional language skills were measured through receptive and expressive language on FLAS. The mean scores on these component skills were compared. The baseline average score on receptive language (224.2) was significantly lower than that at post intervention (329.53) as indicated by the derived t-value (7.05; p<.001). From figure 8 it is evident that all children improved their performance from pre to post test. However, in comparison with others the

With respect to expressive language skills, the children's base line mean score on FLAS was 121.8. After 15 sessions of intervention their performance was observed to have improved. They had learned to use picture or symbols to convey their wishes and desires. They were able to engage in more meaningful social interaction. This was also supported by their post-test performance. The average score on FLAS (182.73) was significantly higher as indicated by the derived t-value (6.01, p<.001). This suggested the positive effect of PECS on communication ability. Figure 9 presents the details of pre and post-test individual performance on expressive

While the experimental group children received PECS based intervention, those in the control group continued with the intervention provided by their respective schools. At the end of intervention period all children were reassessed on FLAS. The second objective of the study

among the children due to factors such as age and intellectual levels.

observed gain was not as much in two of the children.

language skill post intervention.

clear when their pre and post-test individual scores are compared (Figure 7).

224 Autism Spectrum Disorder - Recent Advances

was to compare the post intervention performance of experimental group children to children in the control group. The difference was analysed for statistical significance (Table 3.)


**Table 3.** Comparison of post-test composite mean scores of experimental and control groups on FLAS

The resultant t- value (5.92, p<.001) was highly significant. This indicated that PECS based intervention was effective than traditional intervention methods for children with autism.. Figure 10 shows the quantitative difference in performance of children in experimental and control groups.

Every child except one in the experimental group performed better than his/her counterpart in the control group. Some experimental children scored significantly higher than their control group peers. A similar trend was seen when mean scores on receptive and expressive language skills were compared (refer to Figure 11)

The children in the experimental group performed better on FLAS component skills. But the difference was more in receptive language. This might be due to the limited number of intervention sessions. Due to the short duration of intervention, the experimental group children could not demonstrate similar gain in both receptive and expressive language skills. However, in order to ensure that acquisition and demonstration of newly acquired functional communication ability was not limited to intervention setting, the experimental group individual scores on FLAS was correlated with the respective scores given to children by their parents on FLAS (P). The parents administered FLAS (P) on their respective children at the end of the intervention period. Their children's gain in communication skills was reported by the parents. When FLAS (P) scores were correlated with scores on FLAS using Product Moment method, a high correlation (r = 0.89) resulted between the two sets.
