The kruskal wallis test is a direct generalisation of

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Unformatted text preview: ed in the company is more likely to be affected by internal organisational factors such as management’s perception of decision analysis and the corporate culture than the techniques or approach used by other companies. In this case, the explanatory variable, the organisations’ use of decision analysis techniques and concepts, has multiple levels and hence, the problem should be regarded as a “several sample” problem. This process highlights three tests as being applicable in this case: Kendall’s test for correlation, Spearman’s test for correlation and the Kruskal Wallis test. First, consider the two correlation tests. Since the two tests rarely produce different results (Leach, 1979 p192) and the researcher is familiar with the Spearman correlation test, it will be used here. The procedure for carrying out the Spearman test for correlation 175 is outlined in Appendix 3. The null and alternative hypotheses that will be tested using the Spearman test for correlation for each performance measure are: H10: There is no or a negative relationship between the ranking of sampled companies with respect to the performance measure under investigation and the ranking of the sampled companies with respect to decision analysis sophistication in investment appraisal. H11: There is a positive relationship between the ranking of sampled companies with respect to the performance measure under investigation and the ranking of the sampled companies with respect to decision analysis sophistication in investment appraisal. The Kruskal Wallis test is a direct generalisation of the Wilcoxon Rank Sum test to three or more independent samples. The test attempts to decide whether the samples of scores come from the same population or from several populations that differ in location. It assumes that the data are independent and ordinal. The procedure for carrying out the test is outlined in Appendix 4. Since PR and TBV are two of the criteria which are most indicative of the results of recent, past investment decisionmaking (section 7.4), Kruskal Wallis tests will only be carried out on them (there is insufficient data for a Kruskal Wallis test for PSR). The null and alternative hypotheses to be tested will be: H20: The TBV (or PR) of each company is independent of the decision analysis sophistication rank achieved by each company H21: The TBV (or PR) of each company come from populations that differ in location according to the rank achieved by each company in the assessment of decision analysis sophistication. If a significant result is achieved with this test for either or both of the criteria the locus of the difference will be identified by carrying out multiple comparisons using the Wilcoxon Rank Sum test. This test is also outlined in Appendix 4. The following section investigates these hypotheses by calculating the appropriate test statistics. 176 7.6 RESULTS In this section, the results of the statistical tests are presented and the null hypotheses are accepted or rejected as appropriate. The Spe...
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This document was uploaded on 03/30/2014.

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