Table 4.
Comparison of observed and DIF-adjusted mean Parental Stress scores and mean Lack of Parental Satisfaction scores in groups affected by differential item functioning in the total sample
| DIF-groups (N) | Observed scores | Adjusted scores | |||
|---|---|---|---|---|---|
| Mean | SE | Mean | SE | Biasa | |
| Parental stress subscalea | |||||
| Sampleb | |||||
| Ordinary (571) | 4.07 | .08 | 4.45 | .08 | −.38 |
| Behavior (234) | 5.14 | .14 | 4.77 | .14 | .37 |
| Parent educationc | |||||
| Secondary or less (203) | 4.90 | .15 | 4.52 | .15 | .38 |
| Tertiary (602) | 4.21 | .08 | 4.55 | .08 | −.34 |
| Lack of parental satisfaction subscale | |||||
| Sampled | |||||
| Ordinary (571) | .69 | .04 | .69 | .04 | .00 |
| Behavior (234) | .92 | .09 | .75 | .08 | .17 |
SE Standard error
aAs the Parental Stress subscale is affected by DIF from more than once source, any reference group within a DIF-variable is adjusted to account for the other sources of DIF, and thus all groups are biased if not adjusted
bDifferences in observed mean scores (χ2 (1) = 45.4, p < .001)., and adjusted mean scores (χ2 (1) = 4.1, p = .042)
cDifferences in observed mean scores (χ2 (1) = 15.7, p < .001), and adjusted mean scores (χ2 (1) = 0.0, p = .849)
dDifferences in observed mean scores (χ2 (1) = 6.2, p = .01), and adjusted mean scores (χ2 (1) = 0.6, p = .442)