Page 244 - DMGT209_QUANTITATIVE_TECHNIQUES_II

Unit 12: Hypothesis Testing

procedure you run in SPSS. It is used in two ways: (1) as a criterion level where you, the researcher Notes
have arbitrarily decided in advance to use as the cutoff where you reject the null hypothesis, in
which case, you would ordinarily say something like “setting p at p > .65 for one-tailed or two-
tailed tests of significance allows some confidence that 65% of the time, rejecting the null
hypothesis will not be in error”; and more commonly, (2) as a expression of inference
uncertainty after you have run some test statistic regarding the strength of some association or
relationship between your independent and dependent variables, in which case, you would say
something like “the evidence suggests there is a statistically significant effect, however, p < .05
also suggests that 5% of the time, we should be uncertain about the significance of drawing any
statistical inferences.”

Task A study was conducted to measure the motivation level of each of the category of
managers. Formulate a hypothesis, suggesting testing procedures to show that there is no
relation between the category of managers and the level of motivation.

Self Assessment

Fill in the blanks:
5. To reduce the risk, use a = 0.01 which implies that we are prepared to take a …………..risk
i.e., the probability of rejecting a true hypothesis is 1%.
6. In parametric tests, it is assumed that the data follows …………………
7. ……………………test involves the greater risk of accepting a false hypothesis and thus
committing a Type 2 error.
8. A ……………….sometimes called an uncertainty or probability coefficient, is based on
properties of the sampling distribution.

12.6 Summary

 Hypothesis testing is the use of statistics to determine the probability that a given
hypothesis is true.
 The usual process of hypothesis testing consists of four steps.

 Formulate the null hypothesis and the alternative hypothesis.
 Identify a test statistic that can be used to assess the truth of the null hypothesis.
 Compute the P-value, which is the probability that a test statistic at least as significant as
the one observed would be obtained assuming that the null hypothesis were true.
 The smaller the -value, the stronger the evidence against the null hypothesis.

 Compare the -value to an acceptable significance value a.
 If , that the observed effect is statistically significant, the null hypothesis is ruled out, and
the alternative hypothesis is valid.

12.7 Keywords

Alternate Hypothesis: An alternative hypothesis is one that specifies that the null hypothesis is
not true. The alternative hypothesis is false when the null hypothesis is true, and true when the
null hypothesis is false.

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