This paper is aimed at identifying the invariants employed by teachers to understand the variation concept. Ten Mathematics teachers were involved in this research, in a process of continuing formation lasting 54 hours. During the early discussions with these teachers it was possible to identify the absence of such concept among them. When working with quantitative data we realized the teachers knew the algorithm for the calculation of standard deviation, although they were not able to interpret the results they obtained. At the end of the process we used an exercise to diagnose possible changes in the conceptual field of variation. Only one lady teacher was able to clearly identify data variation and the mean variation. Although we worked with such a small groups of teachers, we could notice that data variation is an intuitive concept, which does not happen in terms of standard deviation, which is extremely hard to interpret.
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