Abstract:
Children with autism often fail to acquire functional speech. Language acquisition is considered an important skill as it leads to the development of skills in other areas. Applied Behaviour Analysis has developed several procedures which are effective in teaching language skills; however, scientific validation of these procedures is needed through further research. Kodak and Clements (2009) were concerned that sometimes children failed to acquire verbal operants with mand- and tact-only procedures. They investigated the use of a combination of procedures and found that concurrent echoic with mand and tact training was successful in facilitating the acquisition of mands and tacts in a boy with autism. In a replication and extension of the Kodak and Clements study, three boys and a girl with autism received mand and tact training for three operants each. Two of the boys acquired all operants without requiring concurrent echoic training. The third boy did not complete the study. The girl participant required concurrent echoic training on one mand only. When data for concurrent echoic with mand training showed a declining trend, it was hypothesised that the mand was losing its value as a reinforcer. When changed to tact training, concurrent echoic training resulted in acquisition of the operant as a tact. Generalisation probes found that acquisition of the operants for all participants was transferred across people, settings, and time. Findings show that mand- and tact-only training can be successful in facilitating the acquisition of verbal operants. When single procedures fail, findings show that concurrent echoic training may be effective in facilitating acquisition. Social validity data show that the teachers and one parent rated the study as acceptable. Limitations and strengths of the project are discussed plus recommendations for future research.