Variation is a fundamental concept in statistics literacy; standard deviation is part of compulsory school curriculum in Brazil. The objective of this study is to explore reasoning about variability by teachers, using the model proposed by Garfield (2002). The sample was composed of nine in-service mathematics teachers who took part in a teacher-training course on statistics. An experimental focus made it possible for them to experience all the steps of a statistics research project in which the course content was designed to expose the reasoning about variability employed by these teachers. We identified an oscillation between idiosyncratic and procedural levels, but no teacher showed complete reasoning about variation. The most prevalent reasoning employed was verbal, when teachers interpreted standard deviation as a measure of variation among observations.
The CAUSE Research Group is supported in part by a member initiative grant from the American Statistical Association’s Section on Statistics and Data Science Education