Leadership

The leadership construct includes 12 questions/variables shown in Table 9. The sample size for the whole construct (regardless of phases) is 142 including all projects in the database. The data is normally distributed based on the histogram shape Figure 8 and also based on the skewness and kurtosis Table 13. The internal consistency/reliability of the construct is excellent Table 15. Descriptives of leadership construct are shown in Table 19 below.

As mentioned before, for t-test, the normality of the leadership construct should be tested in each phase, namely, conceptualization, planning, and execution. This

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investigation is already done in the methodology section using skewness and kurtosis which is presented in Table 12. The table suggest that leadership construct in

conceptualization phase is not normal. The distribution histograms of the phases are shown in Figure 9, Figure 10, and Figure 11.

TABLE 19DESCRIPTIVES OF LEADERSHIP CONSTRUCT

Descriptive Statistics

N Range Minimum Maximum Mean Std. Deviation Variance

Leadership 142 2.81 2.11 4.91 3.7593 .52497 .276

Valid N (listwise) 142

FIGURE 8DISTRIBUTION HISTOGRAM OF LEADERSHIP CONSTRUCT REGARDLESS OF DIFFERENT PHASES

FIGURE 9DISTRIBUTION HISTOGRAM OF

LEADERSHIP CONSTRUCT IN CONCEPTUALIZATION PHASE

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Descriptives of leadership construct in different phases are available in Table 20 including sample size, mean, standard deviation, and standard error mean.

TABLE 20DESCRIPTIVES OF LEADERSHIP CONSTRUCT IN DIFFERENT PHASES

The results of independent-samples t-test and Mann-Whitney U test are presented in 3 categories as follows.

Group Statistics

Project phase N Mean Std. Deviation Std. Error Mean Leadership Conceptualization 29 3.8007 .58843 .10927

Planning 54 3.6743 .50124 .06821

Execution 56 3.8235 .51376 .06865

FIGURE 10DISTRIBUTION HISTOGRAM OF LEADERSHIP CONSTRUCT IN PLANNING PHASE

FIGURE 11 DISTRIBUTION HISTOGRAM OF LEADERSHIP CONSTRUCT IN EXECUTION PHASE

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4.1.1.1 Conceptualization and planning

Descriptives of the 2 phases are shown in Table 20 including sample size, mean, standard deviation, and standard error mean.

Based on Table 12, the leadership construct in conceptualization phase is not normal because its skewness is slightly (0.03) out of the acceptable range. Therefore, it is necessary to conduct both parametric and nonparametric tests here, i.e., independent-samples t-test and Mann-Whitney U test.

Table 21 presents the results of independent-samples t-test (the parametric test) which also comprises the results of Levene's Test for Equality of Variances. According to the table, the variances of the phases is approximately equal and there is no significant difference in leadership between conceptualization and planning phases of the projects because the significance level is greater than 0.05.

The results of Mann-Whitney U test (the nonparametric test) together with its descriptives are presented in Table 22 and Table 23. Based on Table 23, there is no significant difference in leadership between conceptualization and planning phases of the projects because the significance level is greater than 0.05.

T

ABLE

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^THE RESULTS OF INDEPENDENT-SAMPLES T-TEST FOR LEADERSHIP IN CONCEPTUALIZATION

-PLANNING COMPARISON

Independent Samples Test Levene's

Test for Equality of

Variances t-test for Equality of Means

F Sig. t df FOR LEADERSHIP IN CONCEPTUALIZATION-PLANNING COMPARISON Leadership Conceptualization 29 47.03 1364.00

Planning 54 39.30 2122.00

Total 83

Test Statistics

Leadership Mann-Whitney U 637.000

Z -1.394

Sig. (2-tailed) .163

a. Grouping Variable: Project phase

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4.1.1.2 Conceptualization and execution

Descriptives of the 2 phases are shown in Table 20 including sample size, mean, standard deviation, and standard error mean.

Based on Table 12, the data regarding the conceptualization phase of leadership construct is not normal. Thus, it is necessary to conduct a Mann-Whitney U test in addition to the t-test.

Table 24 presents the results of independent-samples t-test. It also comprises the results of Levene's Test for Equality of Variances. According to the table, the variances of the phases is approximately equal and there is no significant difference in leadership between conceptualization and execution phases of the projects because the significance level is greater than 0.05.

The results of Mann-Whitney U test together with its descriptives are presented in Table 25 and Table 26. Based on Table 26, there is no significant difference in leadership between conceptualization and execution phases of the projects because the significance level is greater than 0.05.

TABLE 24THE RESULTS OF INDEPENDENT-SAMPLES T-TEST FOR LEADERSHIP IN CONCEPTUALIZATION-EXECUTION COMPARISON

Independent Samples Test Levene's

Test for Equality of

Variances t-test for Equality of Means

F Sig. t df

ip Equal variances

assumed .766 .384 -.184 83 .854 -.02277 .12357 -.26853 .22300 Equal variances

not assumed -.176 50.4 .861 -.02277 .12905 -.28191 .23637

TABLE 25THE DESCRIPTIVES OF MANN -WHITNEY U TEST FOR LEADERSHIP IN CONCEPTUALIZATION-EXECUTION PHASE COMPARISON

TABLE 26THE RESULTS OF MANN-WHITNEY U TEST FOR LEADERSHIP IN CONCEPTUALIZATION-

EXECUTION PHASE COMPARISON

4.1.1.2.3 Planning and execution

Descriptives of the 2 phases are presented in Table 20 including sample size, mean, standard deviation, and standard error mean.

Ranks Leadership Conceptualization 29 44.34 1286.00

Execution 56 42.30 2369.00

Total 85

Test Statistics

Leadership Mann-Whitney U 773.000

Z -.362

Sig. (2-tailed) .718

a. Grouping Variable: Project phase

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Table 27 presents the results of independent-samples t-test. It also comprises the results of Levene's test for Equality of Variances. According to the table, the variances of the phases is approximately equal and there is no significant difference in leadership between planning and execution phases of the projects because the significance level is greater than 0.05.

The results of Mann-Whitney U test together with its descriptives are presented in Table 28 and Table 29. Based on Table 29, there is no significant difference in leadership between planning and execution phases of the projects because the significance level is greater than 0.05.

TABLE 27THE RESULTS OF INDEPENDENT-SAMPLES T-TEST FOR LEADERSHIP IN PLANNING-EXECUTION COMPARISON Independent Samples Test

Levene's Test for Equality of

Variances t-test for Equality of Means

F Sig. t df LEADERSHIP IN PLANNING-EXECUTION PHASE COMPARISON

TABLE 29THE RESULTS OF MANN-WHITNEY U TEST FOR LEADERSHIP IN PLANNING-EXECUTION

PHASE COMPARISON

In document Factors that Affect Transaction Cost in Different Project Phases (sider 67-72)