A Hypothesis
Importance of hypothesis Types of hypothesis Null Hypothesis
Alternative Hypothesis
The two types of alternative hypotheses are directional hypotheses and non-directional Hypotheses. A non-directional alternative hypothesis states that the null hypothesis is wrong. A non-directional alternative hypothesis does not predict whether the parameter of interest is larger or smaller than the reference value specified in the null hypothesis. Whereas a directional alternative hypothesis states that the null hypothesis is wrong, and also specifies whether the true value of the parameter is greater than or less than the reference value specified in the null hypothesis. The advantage of using a directional hypothesis is increased power to detect the specific effect you are interested in. The disadvantage is that there is no power to detect an effect in the opposite direction. Derivation of Hypothesis Deductive: Hypothesis testing 1. Specify H0 and HA – the null and alternative hypotheses (a) H0: E(X) = 10 (b) H0: E(X) = 10 (c) H0: E(X) = 10 HA: E(X) <> 10 HA: E(X) < 10 HA: E(X) > 10 Note that, in example (a), the alternative values for E(X) can be either above or below the value specified in H0. Hence, a two-tailed test is called for – that is, values for HA lie in both the upper and lower halves of the normal distribution. In example (b), the alternative values are below those specified in H0, while in example (c) the alternative values are above those specified in H0. Hence, for (b) and (c), a one-tailed test is called for. 2. Determine the appropriate test statistic 3. Determine the critical region
4. Compute the value of the test statistic 5. Make a decision Decision problem Type I Error: Type II Error: In conclusion, we need the null hypothesis to determine if there is a difference between the groups being tested or not. Without it, we would be swamped with possibilities making it almost impossible to test. | Journals | Instructions| Submission | |