There seems to be much controversy about the use of DTI...and strangely, its use is often discouraged. But the concerns may be misplaced and are more a function of myth and misunderstanding. First, it needs to be said that DTI is not an intervention (EIBI, DIR, TEACH are interventions). There is no such thing as "DTI Intervention"... One doesn't "do" DTI, one uses it. It is a tool, a teaching procedure, like many others on which we rely in our teaching. Like any tool, we learn how to use it and when it's called for.
“EIBI for children with autism is a complex approach based on concepts and principles of applied behavior analysis. Discrete trial instruction is one of many instructional methods that can be used in EIBI. Its effectiveness depends on factors such as quality of curriculum development (competency of curriculum designer), application of complimentary instructional methods and ongoing analysis and adjustments. As with any method, DTI has limitations, but a careful analysis reveals that much of the criticism of DTI may be due to inadequate curriculum development and inappropriate use rather than to the method itself”. (For more on this in detail, see Lund, in Autism Encyclopedia: The Complete Guide to Autism Spectrum Disorders)
And when it comes to teaching a child a language, effective intervention is highly demanding. Not only is a sufficient 'tool box' required, but it requires meticulous attention to detail, a thorough knowledge of all the elements that need to be in place, what it takes to get them in place, how to engineer disparate constituent linguistic abilities so that greater linguistic complexity delvelops, and how to analyze things when things are not moving so well.
Additionally, children need to learn the rudiments and constituents of a language. Those constituents need to be engineered for use across innumerable circumstances across a multitude of activities and transactions. It is our job to be able to identify under which circumstances which linguistic feats are required. Knowing when and how to introducesuch activity, and which concepts can and should be uploaded into those activities, and knowing when and how, within those activities new concepts can and should be introduced. This is not simply a matter of teaching mands, tacts and intraverbals.
Thoughtfully and thoroughly crafted intervention employs a 'teach to build-engineering' approach vs. a 'teach and hope' approach. Therefore, things are taught for a reason and not simply so that they can be checked off as 'done' or 'mastered' and thrown into mastered or maintenance lists. Mastery is most often prgressive. Things are 'done' when they are effortlessly put to use within a linguistic practice.