Concepts of the mean

What does research suggest is important for students when developing concepts of the mean?

Allowing students to develop early, informal experiences of the mean may help them develop better conceptual understanding and reasoning skills rather than learning the procedure by rote first
The mean is complex and should not be oversimplified or taught formally too early; it may be less intuitive to students than the median or mode
It is important that the mean be considered alongside other measures like shape and spread and placed within the bigger picture of a statistical toolkit rather than overemphasised
There are multiple models to aid in conceptual understanding of the mean such as a balance point, fair share and ratio model, which students should have the opportunity to consider; it may be useful to start with the fair share model as the simplest
Zero values and the context of the data are important to consider alongside calculation of the mean
The mean is an example of an abstract mathematical construction and time is required for students to explore it deeply
Students should have the opportunity to discover that the mean is useful in comparing groups of unequal size when appropriate but that it is not always a typical value