There are a number of instructional approaches available within ABA, each of which is uniquely suited to address specific deficits in learners with Autism Spectrum Disorders. Clinicians can utilize a combination of Discrete Trial Instruction (DTT), naturalistic strategies, and rate-building procedures to maximize the acquisition, generalization, and availability of skills. Treatment integrity protocols are essential in training staff, in providing ongoing feedback to staff, and in ensuring high quality instruction for this diversity of instructional techniques. Key words: Autism Spectrum Disorders, Discrete Trial Training, naturalistic strategies, rate-building procedures, staff training and feedback ********** INTENSIVE TEACHING Discrete trial training (DTT) uses repetition and sequenced instruction to build core skills in students with autism (Lovaas, 1981; Lovaas, Koegel, Simmons, & Long, 1973; Smith, 1993). It has been successful in teaching a wide variety of skills in a structured, formalized context. Elements of its effective use include errorless learning procedures (e.g., Etzel & LeBlanc, 1979; Lancioni & Smeets, 1986; Terrace, 1963; Touchette & Howard, 1984) and task variation and interspersal (e.g., Dunlap, 1984; Mace, Hock, Lalli, West, Belfiore, Pinter, & Brown, 1988; Winterling, Dunlap, & O'Neill, 1987; Zarcone, Iwata, Hughes, & Vollmer, 1993). These strategies diverge from some historical applications of DTI, which often utilized blocks of identical target trials and procedures which allowed for repeated errors. Discrete trial instruction is still very useful for teaching skills to children with autism, and its utility has not been eliminated with the emphasis on more naturalistic approaches. DTT is well suited to teaching skills requiring repetition, to teaching skills that are not intrinsically motivating, and to building solid repertoires of tacting, imitation, and receptive skills (e.g. Sundberg & Partington, 1998; 1999). Naturalistic Teaching Over the past two decades within ABA, there has been a strong focus on the use of naturalistic teaching methodologies to meet the needs of learners with autism. Incidental teaching emphasizes getting an elaborated response from the individual, after they have initiated interest in an item or a topic (Hart & Risley, 1982). Incidental teaching has been shown to be a powerful instructional methodology for building initiation skills and a wide variety of language and conversation skills (e.g., Farmer-Dougan, 1994; McGee, Krantz, & McClannahan, 1985; 1986). Furthermore, incidental teaching procedures have been shown to have substantial generalization advantages, compared to discrete trial teaching (McGee, Krantz, & McClannahan, 1985). These are substantial benefits, as the strength of DTT is in building responsivity, and relative weaknesses include failure to build initiation skills or generalize without additional training. In incidental teaching, the teacher arranges the environment to spark the learner's interest. The learner then initiates a request or a conversation about a particular item or topic. The teacher prompts an elaboration of that initiation, and a more elaborate communication from the learner results in access to the desired item (Fenske, Krantz, & McClannahan, 2001). One of the most substantial advantages of an incidental approach over a DTT approach is that the learner is leading the teaching interaction. The learner's interests set the occasion for and drive the instruction (Fenske, Krantz, & McClannahan, 2001). Incidental teaching continues to be an excellent way to build spontaneity, increase initiation, and shape the complexity and sophistication of communication. Other naturalistic methodologies within ABA have emphasized learner interests. Pivotal Response Training (PRT) and Natural Language Paradigm (NLP) emphasize the use of intrinsically motivating materials, teaching in natural contexts, and using the child's interests to guide instruction in language (Koegel, Koegel, & Surrat, 1992; Koegel, O'Dell, & Koegel, 1987; Laski, Charlop, & Schreibman, 1988). …