In The Realist Novel Dennis Walder provides you with an extract from a detective novel to identify, and suggests that you'll find this relatively easy because it contains certain features that we expect in such a work. In other words, we each have a mental set of expectations that we use to categorise writing.
How would you categorise these extracts, all of which are taken from novels? Think about your reasons for suggesting a particular category.
How did you get on? The first extract is from an historical novel (Dunnett, 1993, p. 11). We can guess that it's set in the past because the detailed description of Edinburgh doesn't sound like a modern town. We know it's from a novel since, in the last paragraph of the extract, we are allowed to share a piece of information that one of the characters has been given: ‘The King's Wark, Anselm Adorne had been told.’ Anselm Adorne did exist – he was a merchant and magistrate in Bruges in the second half of the fifteenth century – but Edinburgh is described as he sees it, and this we know can only be a fictional reconstruction. This is a good example of what historical novels can do: they can imaginatively recreate the past, peopling it both with characters who really existed and with characters who are completely fictional.
The second extract is from a popular romance (Mortimer, 1980, pp. 12–13). We know this, I think, because of the emphasis on the smouldering sexuality of the male character and the admiring response of the female character to him. They are stereotypes, placed in a stereotypical situation, although it's perhaps worth pointing out that the male figure has sound literary antecedents in the form of Heathcliff and Mr Rochester, from Emily Brontë's Wuthering Heights and Charlotte Brontë's Jane Eyre respectively.
The third extract is science fiction (May, 1982, p. 11). We might deduce this from the unfamiliar situation, the use of strange words such as ‘superficies’ and ‘normal space’ and the fact that the Ship is a space ship, surrounded by stars.
I hope you could classify these extracts without too much difficulty, because you were able to draw on concepts of various kinds of fictional writing, based on your knowledge and experience of reading. This is the kind of classification that Dennis Walder summarises on page 9 of The Realist Novel, although he also points out that these classifications are not fixed or rigid.