Andy Baker

It is week 8 in the UNSW Earth and Environmental Science course, and the class is working towards writing a lab report on Sydney soil lead pollution.

Last week, students used a portable x-ray fluorescence analyser to test soil samples that they had collected from their homes or across UNSW campus.

This week the focus of the class was hypothesis testing. After completing some reading on the subject, the class was asked to come up with some testable hypotheses that might explain their soil lead data. Where ‘testable’ meant that the class had to be able to source any necessary data in class from reliable online databases.

Before all of this, the role of hypothesis testing in science was discussed, how the scientific method might apply to Earth and environmental science datasets, and how philosophers of science might view how science is actually done.

One hundred students later, split into three groups, with upvoting of hypotheses…

Each group agreed on two or three testable hypotheses and with excellent teamwork and management of a shared online database, successfully collected the necessary metadata.

The hypotheses that will be explored next week – Sydney soil lead concentration increases with:

Proximity to the CBD

Proximity to a major road

Increasing population density

Increasing age of suburb