The purpose of this activity is for students to make predictions about future weight and height of a baby based on statistical data.
The background knowledge presumed for this task is outlined in the diagram below:
This activity should be used in a ‘free exploration’ way with an expectation that students will justify the solutions that they find.
The procedural approach (show more)
- The student uses a deterministic approach to predict the height and weight of the baby.
At a procedural level, students need to interpret the data presented in the growth charts. This is evidenced by correctly marking position of the given weight and length on the charts. The horizontal scale varies between charts, on the weight chart the axis is marked in weeks and months. On the length chart the axis is labelled in months and years. Students should also make some statement about the meaning of percentiles.Click on the images to enlarge them. Click again to close.
Predictions for weight and height by these students are unlikely to acknowledge any variation from the percentiles at 6 weeks of age.
The conceptual approach (show more)
- The student acknowledges potential sources of variation in making predictions for the weight and height of the baby.
Students who understand that extrapolation from given data is prone to variability are likely to identify sources of variation. The first of those sources is gender.Click on the images to enlarge them. Click again to close.
Students might also read about projections of weight and height. The baby growth rates are based on breast fed babies and subsequent good nutrition. Students may note that the accuracy of prediction depends on the baby being well-fed, not falling ill, and not have a genetic or hormone related condition. Students might also look up other ways to predict babies’ heights which also acknowledge variation.Click on the image to enlarge it. Click again to close.