It is associated to an alternative hypotheses for which the sign of the potential difference is unknown. A two-tailed test, also known as non-directional, is a method in which the critical area of a distribution is two-sided and tests whether a sample is greater or less than a range of values. Also, it completely disregarding the possibility of a relationship in another direction. A One-tailed tests allow for the possibility of an effect in one direction, so that it is either greater than or less than a certain value, but not both. In a Statistical Test, the tail refers to the end of the distribution of the test statistic for the particular analysis that you are conducting. In most cases, the alternate hypothesis will just be the opposite of the null hypothesis. It is a claim about the population that is contradictory to H0 and what you conclude when you reject H0. The alternative hypothesis is what you might believe to be true or hope to prove true. This means that a population parameter is smaller, greater, or different than the hypothesized value in the null hypothesis (H0). The Alternative Hypothesis, denoted by H1 or Ha, defines there is a statistically important relationship between two variables. If the hypothesis shows a relationship between the two parameters, the outcome could be due to an experimental or sampling error. So, researchers work to reject, nullify or disprove the null hypothesis. If the null hypothesis returns false, it means that there is a relationship in the measured phenomenon. It denoted by H0 symbolizes the null hypothesis of no difference. The Null Hypothesis states that there is no relationship between two population parameters. If Null Hypothesis is rejected, the statistical conclusion is that the Alternative Hypothesis (Ha) is true. The hypothesis-testing procedure involves using sample data to determine whether or not Null Hypothesis (H0) can be rejected. Hypothesis testing is a form of inferential statistics that allows you to draw conclusions about an entire population based on a representative sample. A hypothesis is an educated guess that is made on the basis of some evidence. It can be evaluated with the Box-Tidwell test as discussed by Field 4.The main purpose of statistics is to test a hypothesis.