Significant deficits in language and communication are among the defining features of autism. Special educators working with children presenting Autism urgently require effective, efficient, and practical techniques for teaching basic linguistic skills and the symbolic relationships between stimuli that provide the supporting framework for such skills. Applied behavior analysis (ABA) has proven to be an effective evidence-based approach for this task, and discrete-trial training techniques have featured as a mainstay of this approach. Matching-to- sample (MTS) tasks are a subset of these techniques and are often used to teach symbolic relationships between words and the objects or ideas to which a word may refer. MTS tasks are most often taught by a teacher using flashcards in table-top methods that involve some degree of trial-and-error learning. Unfortunately, only a few published studies have examined how the efficacy of this basic method can be enhanced by manipulating the consequences arranged for correct responses and errors, but these studies suggest significant potential for improvement. The research here addresses this knowledge gap. It involves a component analysis of the error- and preference-correction procedures that have supplemented trial-and-error training on MTS tasks. Three laboratory studies will each use children with autism and compare their rates of learning the intended stimulus associations after different MTS procedures are used. The MTS procedures only differ with respect to an isolated and exaggerated feature of some correction technique. A fourth study, conducted in a classroom using special-education teachers and educationally-relevant stimuli, will assess the social validity of an effective correction procedure from the lab studies. The anticipated outcome of this research is the design and empirical validation of teaching strategies that can either stand alone or supplement others (including those aiming to train in an "errorless" manner) to speed the learning of MTS tasks in people with moderate to severe autism. Specific areas of application include improvements in functional communication capabilities and fundamental linguistic skills for children with moderate to severe disabilities.