I dont even think it's a case of pitching to a given knowledge level, it's a question of understanding what is important to the other person and expressing your

I dont even think it's a case of pitching to a given knowledge level, it's a question of understanding what is important to the other person and expressing yourself in terms that makes sense in that context. The article is written in such a way as to highlight Smith's dismay and frustration due to his colleagues' questions and suggestions. As a reader you are left with no idea why the Redroot does not see that a line cannot be red and green at the same time. In practice this is exactly the bridge that Smith must cross otherwise the meeting ends in disaster. To do this it's not just a case of speaking in simple terms (though this is often effective), it's a case of figuring out what the other people will consider to be 'simple', in practice this /could/ be something quite complicated - especially to Smith since he is not used to thinking in this way.