Chapter 8

Chapter 8

1. Testing of Hypotheses I

   • Hypothesis is usually considered as the principal instrument in research. Its main function is to suggest new experiments and observations.
     • A hypothesis may be defined as a proposition or a set of proposition set forth as an explanation for the occurrence of some specified group of phenomena either asserted merely as a provisional conjecture to guide some investigation or accepted as highly probable in the light of established facts
       • Quite often a research hypothesis is a predictive statement, capable of being tested by scientific methods, that relates an independent variable to some dependent variable.
         • Characteristics of hypothesis
           • Hypothesis should be clear and precise. If the hypothesis is not clear and precise, the inferences drawn on its basis cannot be taken as reliable.
             • Hypothesis should be capable of being tested. In a swamp of untestable hypotheses, many a time the research programmes have bogged down
               • Hypothesis should state relationship between variables, if it happens to be a relational hypothesis.
                 • Hypothesis should be limited in scope and must be specific. A researcher must remember that narrower hypotheses are generally more testable and he should develop such hypotheses.
                   • Hypothesis should be consistent with most known facts i.e., it must be consistent with a substantial body of established facts. In other words, it should be one which judges accept as being the most likely.
                     • Hypothesis should be amenable to testing within a reasonable time. One should not use even an excellent hypothesis, if the same cannot be tested in reasonable time for one cannot spend a life-time collecting data to test it.

2. Hypothesis must explain the facts that gave rise to the need for explanation. This means that by using the hypothesis plus other known and accepted generalizations, one should be able to deduce the original problem condition.

   • BASIC CONCEPTS CONCERNING TESTING OF HYPOTHESES

3. MEASURES OF ASYMMETRY (SKEWNESS)

   • • SIMPLE REGRESSION ANALYSIS
       • Null hypothesis and alternative hypothesis:
         • The level of significance
           • Decision rule or test of hypothesis
             • Type I and Type II errors
               • Two-tailed and One-tailed tests
                 • PROCEDURE FOR HYPOTHESIS TESTING
                   • Test of Hypothesis
                     • Statisticians have developed several tests of hypotheses (also known as the tests of significance) for the purpose of testing of hypotheses which can be classified
                       • Non-parametric tests or distribution-free test of hypotheses
                       • Parametric tests or standard tests of hypotheses