We propose a novel method: “Persona-Conjoint Method” (PCM), which measures the effect of learning in complex business situations. The procedure of PCM is summarized as follows: 1) A persona-set is prepared with an orthogonal array often used in marketing conjoint analysis; 2) The relation between personae’ attributes and learning topics is observed, then and the data is used to detect what stereotypes learners have. 3) The effect of learning is evaluated by the viewpoints of learners on their stereotype. This paper also describes the experimental the proposed method, which suggest that learners’ stereotype affect their awareness.