Читать книгу Analysing Quantitative Data - Raymond A Kent - Страница 49

Many of the codings in the original dataset were illogical or inconsistent; for example, for some questions relating to whether or not they had done particular activities, respondents were given the choice between ‘Yes’, ‘No’ and ‘Don’t know’, while for others it was just ‘Yes’ and ‘No’. In a question asking respondents to indicate how often they had come across adverts for a range of different products, ‘Very often’ was coded 1 and ‘Never’ coded as 6, with ‘Don’t know’ as 7. Besides being counter-intuitive (the higher the score, the less often), this way of coding makes it impossible to use the codes as metric values for summation since ‘Don’t know’ has the highest value. Accordingly, a number of data transformations were needed before analysis could begin. It was also necessary to create new variables additional to those in the questionnaire, for example the number of channels on which respondents had seen adverts for alcohol.