p-Value

The probability value (abbreviated "p-value"), which can range from 0.0 to 1.0, refers to a numeric quantity computed for sample statistics within the context of hypothesis testing. More specifically, the p-value is the probability of observing a test statistic that is at least as extreme as the quantity computed using the sample data. The "probability" is computed using a reference distribution that is generally derived using the null hypothesis. The phrase extreme is usually interpreted with respect to the direction of the alternative hypothesis—if two tailed, then the p-value represents the probability of observing a test statistic that is at least as large in absolute value as the number computed from sample data. Put another way, the p-value can be interpreted as the likelihood that ...