What is a p value? The p-value provides an estimate of how often we would get the obtained result by chance if in fact, the null hypothesis is true. In statistics a result is called statistically significant if it's unlikely to have occurred by chance alone. The most commonly used standard or cutoff is 0.05 or 5%. Because this standard, or cutoff is so important it has a special name. It's called the significance level of a test, and is usually denoted by the Greek letter alpha, so alpha equals 0.05. If the p-value is small, less than 0.05, this suggests that it is more than 95% likely that the association of interest would be present following repeated samples drawn from the population. AKA, a sampling distribution. If the p-value is less than alpha, which is usually 0.05, then the data we got is considered to be rare or surprising enough when the null hypothesis, H 0 is true. And we say, that the data provides significant evidence against the ...
