Within the conceptual framework of comparative discourse linguistics, this article examines the similarities and the differences between Anglo-American and French Usenet newsgroups and builds hypotheses about the implicit rules which govern the respective ethnolinguistic communities. The comparison is focused on cultural perceptions of questions and explanations occurring in the messages posted in these newsgroups. Both discursive operations have different conversational functions in the Anglo-American and the French messages. Their cross-cultural analysis shows that within the Anglo-American newsgroup, the purpose of the discussion is to get a better comprehension of the complexity of (environmental) issues, whereas the purpose within the French newsgroup is to maintain an ordinary conversation between equals.