More sophisticated computer joke programs have yet to be developed. Based on our understanding of the SSTH / GTVH humour theories, it is easy to see why. The linguistic scripts (a.k.a. frames) referenced in these theories include, for any given word, a "large chunk of semantic information surrounding the word and evoked by it [...] a cognitive structure internalized by the native speaker". These scripts extend much further than the lexical definition of a word; they contain the speaker's complete knowledge of the concept as it exists in his world. As insentient machines, computers lack the encyclopaedic scripts which humans gain through life experience. They also lack the ability to gather the experiences needed to build wide-ranging semantic scripts and understand language in a broader context, a context that any child picks up in daily interaction with his environment.