Winitz, Harris. "Grammaticality Judgment as a Funciton of Explicit and Implicit Instruction in Spanish."
The goal of this study was to determine whether implicit instruction or explicit grammar instruction resulted in higher scores on a grammaticality judgment test. The experiment was administered in college Spanish classes. One group of students was taught using implicit instruction: Total Physical Response activities, short reading passages, two Spanish books, and audio-casette listening assignments. Some of the TPR activities included: "pointing to objects, finding items in teh room, and acting out scripts" (36). Their assessments included picture identification and drawing or sequencing that corresponded to what the teacher had said in Spanish (37). This group was also exposed to more comprehensible input in the target language. The control group was taught using explicit instruction including: pronunciation practice, grammatical rules, and vocabulary learned through translation.
The grammaticality judgment test lists sentences in Spanish that are either allowable or not. For example, "La manzana de hombre gordo está en la mesa" is not allowed in Spanish. According to Krashen's theories, quantity and quality of comprehensible input is the key factor influencing language acquisition. This experiment confirmed his theory. Students in the implicit instruction group scored much higher on the grammaticality judgment test that students in the explicit group.
The article talks a lot about the Monitor Hypothesis. I'm still a little confused about this idea. I believe that the main point is that students monitor the output they are producing based on the grammatical rules they have learned. If they are taught implicitly then they are less likely to censor themselves and more likely to produce output, whether correct or incorrect. Learning grammar explicitly causes students to be more self-conscious about what they are saying and therefore less likely to say it. Am I on target?