Abstract
This paper considers methodological issues of awareness during adult second language acquisition. Specifically, the paper deals with the issue of instructional orientations, the issue of biases in knowledge measurement, and the issue of reactivity in the online think-aloud protocol. Detailed reviews of prominent SLA research that has investigated the possibility of implicit SLA reveal that the instruction on implicit learning does not guarantee that learners engage in the implicit learning mode, that the majority of SLA research has employed only tests of “explicit learning” such as untimed grammaticality judgment, and that there is some evidence that the online think-aloud protocol causes negative reactivity particularly when it is metalinguistic in nature.