3.1.1. Procedure of PLS-SEM Assessment
Generally, PLS-SEM is a variance-based structural equation modeling technique that creates linear combinations of the indicators (CCV factors) and subsequently estimates the model parameters using the ordinary least square algorithm [
41]. PLS-SEM components are indicators (CCV factors) and latent groups (CCV-groups). The PLS-SEM model consists of the measurement and structure models, as shown in
Figure 2.
The measurement model displays the relationship between the latent group and its indicators (CCV factors). Two indicators are used in PLS-SEM: reflective indicators (arrows from the latent group to its indicators) and formative indicators (arrows from indicators to their latent group). Reflective indicators are assumed to be caused by the latent group construct they measure. Formative indicators are believed to cause the latent construct they are measuring. Reflective indicators are typically used for constructs that consider latent variables that cause the observed indicators. On the other hand, formative indicators are used when the indicators are seen as distinct factors that define the latent construct. Zeng et al. [
24] argued that the mode of the measurement model, 75.89% of these models, employed only reflectively measured constructs, whereas 11.35% employed both reflective and formative measures. Only a few reviewed PLS-SEM applications included latent group variables with only formative measurement models (9.22%); they also stated that most construction studies utilized reflective indicators. Hence, the use of type indicators in this paper was reflective.
The second model (structure model) represents the relation diagram among the latent group and examines the hypothesis relationships. There are two types of latent groups in PLS-SEM: exogenous and endogenous latent group. An exogenous latent group is often considered the independent group in the model and is used to explain the variance in endogenous variables. On the other hand, the endogenous group is specified to have one or more causal paths leading to them from other groups within the model. The endogenous group is often considered the dependent variable in the model, influenced by the exogenous groups and other endogenous groups. The latent group (EP, IQ, CP, PC, or EF) can be classified as an exogenous and endogenous latent group. The exogenous latent group is an independent latent group that changes other latent groups’ values within the causal model. For example, CP and EF are exogenous latent groups, which cause PC value change as the arrow directed from CP to PC in
Figure 2. Also, EF causes a change to PC, as indicated in
Figure 2, through the arrow emitted from EF to PC. On the other hand, the endogenous is a latent group directly or indirectly influenced by the exogenous latent group. For instance, the PC is an endogenous latent group influenced by EF and CP, as shown by two arrows received in PC from EF and CP in
Figure 2.
After defining all the latent groups and their indicators of the causal model, all relationships among the latent groups need to be evaluated. The primary purpose of the PLS-SEM is to examine the existence of hypothesis relationships among the latent groups. Therefore, the hypothesis relationships between all latent groups were first created. Following a particular methodology, including expert logic, has eliminated these hypotheses’ logic. At this point, the assessment of measurement and structure model are followed to test these hypothesis relationships (accept or reject the relationship). The following explanation of these two assessment models is shown in
Figure 3. It is noted that the measurement assessment model was first performed, followed by the structure model assessment.
Measurement Model Assessment
The measurement model assessments aim to identify the necessary indicators and remove the insignificant ones. This assessment can be performed by examining the impact of changing the indicator’s value to their latent group. This impact can be measured using two validity approaches: construct and reliability validity and discriminant validity.
The construct and reliability validity approach used three measurement coefficients: Cronbach’s alpha, composite reliability, and average variance extracted (AVE). The three coefficients are based on the outer loading of the indicator (factors) and should be more than the threshold value (more than 0.7 for Cronbach’s alpha and composite reliability; more than 0.5 for AVE). The outer loading of the indicator (
l) shall be more than or equal to 0.7. On the other hand, there are two cases when
l is smaller than 0.7 for assessment
construct and reliability. Case 1 represents the indicator’s outer loading value smaller than 0.4. Therefore, the indicator should be eliminated from the model. Case 2 represents the indicator with an outer loading of more than 0.4 and less than 0.7. Thus, in such a case, the elimination of the indicator has no effect on increasing any of the three coefficients (α,
CR, and
AVE) of its construct (group). Therefore, the indicator should remain in the model. Moreover, suppose the omitted indicator leads to an increase in any of the three coefficients of its construct. In that case, the indicator will be deleted from the model (the indicator is nonsignificant) [
23]. As a result, PLS-SEM additionally uses composite reliability to assess the constructs’ internal consistency dependability [
42].
The discriminant validity approach examines if a latent group is unique from other latent groups. The overall goal of this validity approach is to remove the insignificant indicators. Two critical metrics can measure the uniqueness among latent groups: the Fornell–Larcker criterion and cross-loadings. The Fornell–Larcker criterion ensures whether a latent group shares more variance than another latent group variable. Accordingly, each latent group’s square root of its
AVE should be higher than its highest correlation with other latent groups [
23]. Regarding the cross-loadings, an indicator’s loading with the related latent group should be more significant than its loadings with all the other latent groups [
23].
Structure Model Assessment
The structural assessment model aims to test whether the hypothesis relationships are accepted or rejected. This assessment model can be achieved by examining the relation between two latent groups by determining the b coefficient or
p-value. These coefficients and values indicate whether the relation exists or not. Refer to the reference for more details on calculating b and p. [
42]. If p is less than 10%, then the alternative hypothesis (b ≠ 0, there was a relationship between the two latent groups) is accepted. Otherwise, the null hypothesis (b = 0, no relationship between the two latent groups) is accepted.
3.1.2. Build the Causal Model
The causal model depended on using PLS-SEM based on the qualitative and quantitative data. These data were extracted from the questionnaire provided by Alsugair (2022) and the historical 94 KSU projects. The qualitative data represented the degree of impact of the 41 CCV factors, which the 154 participants assessed. The 41 CCV factors with their latent group are shown in
Table 3 [
11]. The quantitative data represent the CCV value for each participant. This CCV value depends on two variables.
The 94 projects undertaken by King Saud University were categorized into distinct groups according to the year of project award, resulting in ten delineated groups labeled from 2010 to 2021.
Table 4 presents the average CCV values for each of these groups corresponding to the specified years. Additionally,
Table 4 provides the means of the CVV values across the ten groups, aligning with the respective years of project award. Therefore, the first variable is the average of the CCV of 94 KSU projects calculated annually (9.72%). The second variable was determined by obtaining the participant’s reliance on historical data for estimating contract costs through questionnaire responses [
11]. Thus, the quantitative data can be computed by multiplying the first and second variables per participant. Accordingly, 154 CCV values were obtained.
The 94 KSU’ projects were grouped based on the year of biding.
Table 4 presents the average of CCV of projects for each year
The causal model using SmartPLS was constructed through three stages (first, second, and third). The general steps can be summarized into three stages. The first stage represents eliminating insignificant latent group, the second stage is building several causal models based on two latent groups, and the third stage represents building the final causal model. The flow charts of the first, second, and third stages are shown in
Figure 4a, b, and c, respectively. More details of each stage and their results are displayed in the following sections.
The primary objective of the first stage is to pinpoint latent groups that do not impact CCV and subsequently eliminate these groups from the forthcoming causal model construction (that will be built in the third stage). The latent groups under scrutiny include IQ, EP, PC, CP, and EF. This phase entails conducting individual hypothesis tests on each of these five latent groups about CCV. The outcome of these tests determines whether a latent group is deemed significant and included in the final causal model or non-significant and excluded. This decision hinges on the significance level of the
p-value, where a
p-value below 0.10 indicates inclusion (significant latent group), and a
p-value exceeding 0.10 signifies exclusion (non-significant latent group). The process of this stage is illustrated in
Figure 5a. Given the five latent groups involved, five distinct models (IQ→CCV, EP→CCV, PC→CCV, CP→CCV, and EF→CCV) were executed during this first stage. Before performing the hypothesis test of the five models, the model was evaluated in terms of construct and discriminant validity.
Table 5 displays the construct validity of the five models at the first stage, and
Table 5 also shows the significant CCV factors for each model. For construct validity, it is noticed in
Table 4 that Cronbach’s alpha and composite reliability of the latent groups for all five models exceeded the threshold value (0.7). In addition, their AVE values were more than the acceptable value (0.5), as shown in
Table 4. These results indicate that the construct validity was satisfied. The discriminant validity was unnecessary because each model had only one latent group. The third column of
Table 5 shows the significant factors for each latent group that satisfied the construct validity. For hypothesis test results,
Table 6 shows the test results of the first stage. The direction of the path is one way from the latent group (EP, PC, EF, and IQ) to the CCV. The
p-value test ranged from 0.0002 to 0.02, less than 0.1. The test indicated accepting the alternative hypothesis (b≠0) that stated a relationship and coefficient (b_i ≠ 0) between latent groups to CCV. Therefore, the five latent groups are significant in the CCV.
The second stage examines any two influences of any two latent groups on CCV. First, there is a need to determine the number models that performed in the second stage, including two logic hypothesis relationships. The primary goal of the second stage is to identify the optimal model comprising two significant latent groups and the CCV, which will serve as the fundamental building blocks for shaping the ultimate model. Based on the total number of latent groups (
) and the number of hypothesis relationships in each model (
), the total number of models that can be generated in second stage was computed based on the permutation formula
[
43], with a total of 30 models. The number of models that contained a nonlogic relationship (hypothesis) (shown in bold hypothesis,
Table 7) was ten models, as shown in
Table 6. Hence, the twenty models were developed based on the expert’s logical hypothesis, as shown in
Table 8. These models were tested using a specific procedure. Thus, a set of steps was developed in this study to achieve the required exam in this stage, as stated below.
Figure 4b illustrates the flowchart of this process.
For example, consider selecting EP and IQ as latent groups. Thus, two hypotheses were created: EP:→CCV and IQ→CCV. The results of the two hypothesis tests indicate that the EP→CCV is accepted while the IQ→CCV is rejected, as shown in
Table 8. Hence, the direction of the IQ→CCV was redirected from CCV to EP, and a new hypothesis was created, IQ→EP, as shown in Model 2 in
Table 7. Based on the magnitude of the
p-value of the hypothesis, the optimal model was selected as Model 4, Model 5, and Model 7, as shown in
Table 7. These models were considered in the third stage.
The purpose of the third stage is to develop the final causal model. This stage has a list of steps repeated until the final causal model latent groups reach significant latent groups.
Figure 4c depicts the process of this stage. The following steps are performed in this stage for each model iteration.
Step 1: Select the best model from the twenty Stage 2 models based on the minimum p-value. Assume there are three latent groups: CCV (first latent group), second latent group, and third latent group.
Step 2: Add an extra latent group (fourth latent group) to the selected model as exogenous to the CCV (first latent group). The added latent group should not be found in the selected model. As a result, a revised model was created with four latent groups (three relationships).
Step 3: Test the hypothesis for all relationships of the revised model.
- ○
Step 3.1: If all three relationships were significant (acceptance relationships), a new model was created, and it consisted of four latent groups.
- ○
Step 3.2: If one of the three relationships were insignificant, the relationship of the added latent group (the fourth one) was redirected from the CCV latent group to the second latent group of the revised model. As a result, the revised model is updated.
- ○
Step 3.3: Test the hypothesis of the revised model relationships.
- ▪
Step 3.3.1: If the p-values of all three relationships are significant (p-value ≤0.1), a new model consisting of four latent groups was created.
- ▪
Step 3.3.2: If the p-value of the one relationship, at least, was insignificant (p-value >0.1), the relationship of the added latent group (fourth group) was redirected from the second latent group to the third latent group. As a result, the revised model is updated.
- ▪
Step 3.3.3: Test the hypothesis of the revised model relationships. If one of the relationships was at least insignificant (p-value >0.1), the added latent group (fourth one) should be deleted.
Step 4: Another extra latent group was added to the new model, and the previous procedure was repeated. The above process and steps continued until all the latent group relationships were tested.
A calculation sample in this stage is illustrated to clarify the proceeding steps. From Step 1, the best Stage 2 models were Model 4, Model 5, and Model 7. These models were combined to create a combined model, which had PC, CP, EF, and CCV, as shown in
Figure 5. The EP was added to the combined model as
exogenous to CCV (Step 2). After that, the hypothesis for all relationships of the revised model, which had PC, CP, EF, EP, and CCV, was tested (Step 3). The results revealed that all hypothesis relationships had
p-values less than 0.10. Therefore, a new model was developed (Step 3.1). The remaining latent group (IQ) was added to the new model (PC, CP, EF, EP, and CCV). The third stage steps were applied until the
p-value of all hypothesis relationships was less than 0.10. Therefore, the final causal model was developed. A simple sketch of the final causal model is shown in
Figure 5. From the causal model’s output, the factors’ outer weights are determined. As mentioned in an earlier section, the main purpose of the developed causal model is to compute the relative weight of the significant factors by normalizing their outer weight values. The relative weight of the factor is represented as (
), where j represents a factor, while
k is the latent group such as (IQ, EP, CP, EF, or PC). Because the developed causal model was performed based on the data that was constructed in 2022, the weight factors were renamed to
.