As tools are adopted by different cultures they become part of that culture, have a history and a social significance which can be contrary to the original intention. They are almost always 'domesticated' [bakhin 1981] They are 'marked' with a rich history and context [de certeau 1984] So in the introduction of tools it is not just a problem of learning the techniques, it is being very mindful of the context, the change in power relationships 'the deeper social significance' [wertsch 1998 p66 But individuals + tools + skills are all iner-dependent. And a difficult to transfer. wertsch use the metaphor, learn to ride one bike and you can ride then all. But this is rare for tools and skill toe so transferable. The complexity of contexts makes it so. From trowler 'cultures and change in higher ed'