Prompting students to self-explain during problem solving has proven to be an effective instructional strategy across many domains. However, despite being called “domain general”, very little work has been done in areas outside of math and science. In this dissertation, I investigate whether the self-explanation effect holds when applied in an inherently different type of domain, second language grammar learning. Through a series of in vivo experiments, I tested the effects of using prompted self-explanation to help adult English language learners acquire the English article system (e.g., teaching students the difference between “I saw a dog” versus “I was the dog”). In the pilot study, I explored different modalities of self-explanation (free-form versus menu-based), and in Study 1, I looked at transfer effects between practice and self-explanation. In the studies that followed, I added an additional deep processing manipulation (Study 2: analogical comparisons) and a strategy designed to increase the rate of practice and information processing (Study 3: worked example study). Finally, in Study 4, I built and evaluated an adaptive self-explanation tutor that prompted students to self-explain only when estimates of prior knowledge were low. Across all studies, results show that self-explanation is an effective instructional strategy in that it leads to significant pre- to post-test learning gains, but it is inefficient compared to tutored practice. In addition to learning gains, I compared learning process data and found that both self-explanation and practice lead to similar patterns of learning and there was no evidence in support of individual differences. This work makes contributions to learning sciences, second language acquisition (SLA), and tutoring system communities. It contributes to learning sciences by demonstrating boundary conditions of the self-explanation effect and cautioning against broad generalizations for instructional strategies, suggesting instead that strategies should be aligned to target knowledge. This work contributes to second language acquisition theory by demonstrating the effectiveness of computer-based tutoring systems for second language grammar learning and providing data that supports the benefits of explicit instruction. Furthermore, this work demonstrates the relative effectiveness of a broad spectrum of explicit learning conditions. Finally, this work makes contributions to tutoring systems research by demonstrating a process for data-driven and experiment-driven tutor design that has lead to significant learning gains and consistent adoption in real classrooms.

This study is conducted to compare the effect of practicing a multilingual approach to a monolingual approach in teaching the English article system for students with multilingual backgrounds. Through a structured experiment in light of sociolinguistic and second language acquisition theories, two different discourses (complexes of signs and practices that organize social existence and social reproduction) structuring different legitimate languages are implemented in each respective approach. In the multilingual approach, all languages in the participants’ language repertoire are legitimized and encouraged, while only Standard English is legitimized in the monolingual approach. Three groups of informants participated in the experiment. Two groups of young informants with low English proficiency, and one group of adult informants with intermediate English proficiency participated in the experiment. The majority of the participants have more than two languages in their language repertoires. The multilingual approach was adopted in one of the young groups and the adult group. The study shows that all informants improved in their use of the English article system, regardless of the different approaches. The informants with lower English proficiency level and with a strongest [-ART] language (language with no articles) improved 40.9% in the multilingual approach, which is almost twice as much as the improvement in the monolingual approach. However, the young informants in both groups tend to be confused about the use of the indefinite article a/an after the exercise. The improvements tend to remain in a longer period of time with the multilingual approach in both the adult group and the young group. In addition, the participants tend to show higher rates of concentration, positive emotional feelings and engagement during and after the multilingual approach. The results suggest that it is beneficial to deploy the multilingual approach, through intentional structuring of the legitimized languages in classroom.