This doctoral dissertation compares thinking aloud alone vs. joint translating (in groups of three) with the same subjects translating two source texts in the two experimental conditions. The subjects are grouped into novices (three first-year students), advanced students (three third-years + three fourth-years), and experts (three professional translators). The theoretical framework is based on Vygotsky's notions of consciousness, metacognition, and the genetic method. The author argues for joint translating as the method to study translating.