Characteristics of the study sample
Table 1. outlines the descriptive statistics of a study sample comprising of 812 individuals across various demographic and work-related variables. The study included 321 males (39.6%) and 491 females (60.4%). Regarding marital status, 208 individuals were single (25.7%), 559 were married (68.8%), 36 were divorced (4.4%), and nine were widowed (1.1%). In terms of working shifts, 555 individuals worked morning shifts (68.4%), 88 worked night shifts (10.8%), and 169 worked both shifts (20.8%). In terms of sector, 578 individuals worked in the government sector (71.2%), 158 in the private sector (19.4%), and 76 were freelancers (9.3%).
Table 1. Descriptive statistics of the study sample
Variables
|
Frequency(%)
|
Gender
|
|
Male
|
321(39.55)
|
Female
|
491(60.45)
|
Marital Status
|
|
Single
|
208(25.7)
|
Married
|
559(68.8)
|
Divorced
|
36(4.40
|
Widow
|
9(1.1)
|
Shift of day
|
|
Morning
|
555(68.4)
|
Nighttime
|
88(10.8)
|
Both
|
169(20.8)
|
Sector
|
|
Government
|
578(71.2)
|
Private
|
158(19.4)
|
Free lancer
|
76(9.3)
|
Total
|
812(100.0)
|
CFA analysis
Factor loading
AMOS 23.0 was utilized to conduct a CFA to assess the measurement models of the ISRS. The CFA results depicted in Figure 1 utilized the overall goodness-of-fit chi-square as a fit index, indicating the data's alignment with a potential tri-dimensional ISRS model. During the analysis, each item's factor loadings were scrutinized and all items were retained based on their satisfactory factor loadings. Notably, the factor loadings between the items (IRSS1 and IRSS16) and their respective constructs (C1=Community Engagement & Civic Responsibility, C2=Community Involvement & Personal Commitment, and C3=Social Concern & Duty) exceeded the recommended threshold (> 0.60).
Model fit
The AMOS-based CFA results, presented in Table 2, indicate a good fit for the ISRS model. The root mean square error of approximation (RMSEA) value of 0.067 fell within the recommended range of <0.05 to 0.10, suggesting a reasonable fit of the model to the data. The comparative fitness index (CFI) score of 0.96 exceeded the standard threshold of >0.95, indicating a robust fit between the suggested model and observed data. The chi-square/df ratio of 4.57 is below the recommended threshold of <5.0, further supports the adequacy of the model fit. While the goodness of fit (GFI) value of 0.95 meets the criterion of >0.95, the adjusted goodness of fit index (AGFI) value of 0.87 slightly falls below the recommended threshold of >0.80. Overall, these results collectively suggest that the ISRS model demonstrates a satisfactory fit to the data, with most fit indices meeting or surpassing standard benchmarks for model evaluation.
Table 2. Confirmatory factor analysis
Measure
|
Recommended Range or Value
|
ISRS results
|
Root-mean square-error of approximation (RMSEA)
|
<0.05–0.10
|
0.067
|
Comparative fit-index (CFI)
|
>0.95
|
0.96
|
Chi-square/df (cmin/df)
|
<5.0
|
4.57
|
Good-of-fit (GFI)
|
>0.95
|
0.95
|
Adjusted goodness of fit-index (AGFI)
|
>0.80
|
0.87
|
Rasch Analysis
Category Probability Curve
In Rasch analysis, category probability curves indicate the likelihood of selecting a response option for a polytomous item based on the underlying trait level. These curves help to assess the response category order and item functioning. They guide adjustments to improve the measurement precision. An assessment was conducted to determine the efficacy of the rating scale in its intended application to the ISRS sub-dimensions. The dataset does not meet the desired 10 responses per subcategory for several options on the ISRS Likert scale, particularly for ISRS1, ISRS4-8, ISRS14, and ISRS16. The fourth and fifth options were consolidated on a Likert scale (see Figure 2, Panel A). This decision was made to obtain more precise evaluations of the task's level of difficulty. An exemplar depiction of the three constructions is displayed for pre- and post-decoding of the scale.
Items and Person fit to the Rasch Model
The MnSq and Zstd values remained within the established boundaries and did not suggest that the data were stable with the Rasch model, as indicated by the suggested indicators. Individual Rasch analyses were performed on each subscale. The MnSq item ranged from 0.05 to 1.08, while the Zstd values ranged from 0.94 1.08. Our goal was to thoroughly examine all items found in any of the three dimensions as long as this instrument was multi-dimensional. The MnSq and Zstd values did not stray from the boundaries required to conform to the Rasch model (Table 3). All items exhibited suitable item fit statistics, as indicated by their item fit values, and their loadings fell within an acceptable range. In addition, the majority of the participants demonstrated a reasonable level of conformity to the Rasch model. However, 36 people were excluded because their data did not align with the model to improve the effectiveness of the scale. Individuals were adequately segregated from each other, as indicated by the person separation index for all three constructs. The ISRS items and their subscales were capable to differentiate and categorize the items, as evidenced by the item separation indices, which varied from 3.48 5.83. The item reliability statistics, which ranged from 0.75 to 0.92, indicated that both the ISRS and its subscales were considered reliable assessments.
Table 3. Rasch model fits and reliability indices.
Scale
|
|
IMnSq
|
Zs-td
|
OMnSq
|
Zs-td
|
Reliability
|
Separation-index
|
Construct1
|
Person
|
0.78
|
-1.02
|
0.99
|
-0.81
|
0.75
|
3.91
|
|
Item
|
0.98
|
0.33
|
0.81
|
0.50
|
0.85
|
4.64
|
Construct2
|
Person
|
1.01
|
-0.58
|
0.77
|
0.05
|
0.92
|
3.48
|
|
Item
|
1.05
|
0.94
|
1.09
|
-0.78
|
0.87
|
4.68
|
Construct3
|
Person
|
0.89
|
-1.2
|
1.1
|
-0.29
|
0.90
|
5.17
|
|
Item
|
0.84
|
0.91
|
0.86
|
1.08
|
0.79
|
4.66
|
IRSRS
|
|
|
|
|
|
0.86
|
5.83
|
Multidimensionality of ISRS
The multidimensionality of the ISRS was assessed using eigenvalues and explained variances. The first component, often known as the "first contrast,” exhibited a significant level of multidimensionality, accounting for 12.1% of the total variability in the data with an Eigen-value of 2.84. The second and third contrasts account for 8.4% and 7.2% of the total observed variance, respectively. The Eigen-values were 2.3 and 1.56. The internal validity of the scale was supported by the point that the most significant initial contrast component accounted for 67.9% of the variation.
The participant hierarchy (Wright Map)
The item map, also known as the participant hierarchy, illustrates the sequential association between participants and items (Figure 3). The participants in this study demonstrated a wider spectrum of characteristics than the items. This provides evidence that there is a correlation between the skill level of the sample and the skill level demonstrated in the items. The test-item targeting was effectively conducted as the average of the item measurements was more than three standard deviations below the average of the person measures.