Christopher's math exam. Themes Social disability In a 2003 interview, Haddon said In big I have to say honestly that I did more research about the London Underground and the inside of Swindon Railway Station, where some of the novel takes place, than I did about Asperger's syndrome. I gave [Christopher] kind of 9 or 10 rules that he would live his life by, and then I didn't read any more about Asperger's because I think there is no typical person who has Asperger's syndrome, and they're as large and diverse a group of people as any other group in society. And the important thing is that I did a lot of imagining, that I did a lot of putting myself into his shoes in trying to make him come alive as a human being rather than getting him right, whatever that might mean. Haddon states on his website that, although he had read "a handful of newspaper and magazine articles about, or by, people with Asperger's and autism" in preparation for writing the book, he knows "very little" about Asperger's syndrome and that Christopher Boone is inspired by two different people. According to Haddon, none of these people can be labelled as having a disability. Haddon added that he "slightly regret[s]" that the term Asperger's syndrome appeared on the cover of his novel. In 2010, in an interview with The Independent, he was described as now thoroughly irritated that the word Asperger's appeared on subsequent editions of the novel, because now everyone imagines that he is an expert and he keeps getting phone calls asking him to appear at lectures. In a critical essay on the novel, Vivienne Muller quotes some praise by experts on disability theory: In its presentation of Christopher's everyday experiences of the society in which he lives, the narrative offers a rich canvas of experiences for an ethnographic study of this particular cognitive condition, and one which places a positive spin on the syndrome. The reader in this instance acts as ethnographer, invited to see what Mark Osteen claims is a 'quality in autistic lives that is valuable in and of itself'. Along similar lines, [Alex] McClimens writes that Haddon's novel is 'an ethnographic delight' and that 'Haddon's achievement is to have written a novel that turns on the central character's difference without making that difference a stigmatising characteristic. Muller adds that the novel works