Methods. Children were interviewed individually at school and requested to write
‘as you used to when you were just beginning to write’. This question was repeated for oneyear-
intervals until child’s current age was reached; anticipation of writing next year was
also requested. Children’s responses were coded into descriptive categories. A multiple
correspondence factorial analysis studied the relations among response categories,
school grade and sociocultural environment. On the basis of these results, categories
were ordered into a Guttman scale