A study was conducted to evaluate the relationship between length of time taking drug X and size of tumor. The correlation coefficient , r,signifies the linear relationship between two variables. The value of r is 0.21 , which is positive and small . The positive value of r signifies that there is aa direct relation between length of time taking drug X and size of tumor. The p value is the probability that the null hypothesis is actually correct. The null hypothesis is in this case is that there is no linear relation between length and time. The p value is less than 0.01, which means that the linear relation is significant .The p value is not the measure of the strength of the evidence. Alternatives like the model likelihoods or the model probabilities can be used for such purpose. Instead of p value we can look at the distribution of the test statistic involved and try to interpret the value of r from there