In areas covering a wide variety of issues such as health, road safety, transport use and consideration of the environment, there are campaigns to change the way that people behave. It may be to drink less alcohol, to drive more safely, to use the car less or to reduce energy consumption. Perhaps the most famous in the Australian context were the ‘Life. Be in it.’ and the ‘Slip! Slop! Slap!’ campaigns. In all these situations there is a need to assess how well the campaigns worked, in order to measure their effects and to determine how to do better next time.
Measuring behaviour change is always a challenge because people are rarely objective about their own behaviour. Far too often people believe – or at least say they believe – that they have “done the right thing” and made a change for the good when in reality they have made little or no change. If change has occurred, it can sometimes be difficult to say it was due to the campaign and not due to something else such as changes in economic circumstance, health, or even the weather.
Data Analysis Australia uses two key principles when evaluating behaviour change.
The first principle is to measure real and relevant outcomes. For example, in road safety, it is a reduction in crashes, injuries and fatalities. In water efficiency projects, it is a measurable drop in water consumption. Focusing on real change removes the subjectivity of both the public (“we think we have changed”) and the campaign personnel (“we think they have changed”).
The second principle is to use proven statistical methods for eliminating extraneous influences that may be confused with the effect of the campaign. Statistical solutions include:
- The use of a control group — a separate but similar group not exposed to the campaign, but likely to be exposed to similar extraneous factors; and
- The use of a statistical model to adjust for known extraneous factors — for example a regression model for the effect of weather.