 ambient radioactivity typical of the surrounding air and harmless objects. We can then calculate how likely it is that the null hypothesis produces 10 counts per minute. If the null hypothesis predicts (say) on average 9 counts per minute and a standard deviation of 1 count per minute, then we say that the suitcase is compatible with the null hypothesis. (This does not guarantee that there is no radioactive material, just that we have no reason to believe it); on the other hand, if the null hypothesis predicts 3 counts per minute and a standard deviation of 1 count per minute, then the suitcase is not compatible with the null hypothesis, and there are likely other factors responsible to produce the measurements.The test described here is more fully the null-hypothesis statistical significance test. The null hypothesis is a conjecture made solely to be falsified by the sample. Statistical significance is a possible finding of the test – that the sample is unlikely to have occurred by 