According to a Vygotskian approach, apprenticeship and cognitive development are linked with the internalization of significant function of language signs, namely with the ability to use words as conceptual tools. Such an internalization is not possible without social mediation and meaning negotiation, within (or consecutively to) an interactive situation. Because within this socio-cognitive process (both inter-individual and intra-individual), linguistic signs play a principal role, a logical analysis of the interlocution seems to be a powerful way to study interlocutive processes: It permits us to understand how semiotic mediations can produce, via exchanged speech acts, new knowledge and new social and cognitive tools. However, we will evoke some theoretical and methodological problems encountered in interaction analysis with young children: the validity (i) of transcription of the reality (coding is transforming, more or less); (ii) of interdiscusive corpus analysed (How can we transcribe punctuation of discourses as well as affects and its perlocutory aims? Are chosen sequences relevant to be analysed?); and (iii) of the researcher's inferences regarding the effective mechanisms; the importance of nonverbal signs within a conversation; and the difficulty (i) of abstracting structures of transactions and (ii) of measuring both the impact of subject's previous social and cognitive experience and representations concerning the partner.