The odds ratio

To find relations between the factors influencing wind turbine perception by its surrounding residents, the odds ratio test was used. This test calculates the chance with which an effect occurs in the presence or absence of a crucial factor.

For example, the WINDFARMperceptionroject calculated whether the chance of hearing the wind turbine (= the effect) depends on being able to see (= the possible crucial factor) the concerning turbine.

The report shows an odds ratio of 4.16 with a confidence interval of 2.717 – 6.372. The chance one hears a wind turbine is 4.16 times as high when the turbine is visible than when it’s not.

Because not all wind turbines were taken into the study, this value might differ somewhat in the field. Therefore the confidence intervals are calculated. In a field situation the chance of hearing a wind turbine will increase with 2.717 to 6.372 when the turbine is visible.