Table 2.
Parameter estimates of the model examining the mediation role of spatial ability in the relation between constructive play and word problem-solving performance.
| Model | Estimate | SE | p | CI (lower) | CI (upper) |
|---|---|---|---|---|---|
| Model without mediator | |||||
| Intercept | 4.57 | 1.11 | <0.01 | 2.36 | 6.78 |
| CP→WPS (c) | 0.38 | 0.14 | <0.01 | 0.11 | 0.66 |
| Sex→WPS | -1.44 | 0.60 | <0.05 | -2.63 | -0.24 |
| R2 (y, x) | 0.19 | – | – | – | – |
| Model with mediator | |||||
| Intercept | 2.86 | 1.04 | <.01 | 0.78 | 4.94 |
| Model 1: SP as dependent variable | |||||
| CP→SP (a) | 0.75 | 0.41 | <0.05 | -0.06 | 1.56 |
| Sex→SP | -3.33 | 1.79 | 0.07 | -6.90 | 0.25 |
| Model 2: WPS as dependent variable | |||||
| SP→WPS (b) | 0.16 | 0.04 | <0.001 | 0.09 | 0.23 |
| CP→WPS (c’) | 0.26 | 0.12 | <0.05 | 0.02 | 0.51 |
| Sex→WPS | -0.89 | 0.54 | 0.10 | -1.97 | 0.18 |
| Indirect effects (a x b) | 0.12 | 0.08 | <0.05 | 0.128 | 0.27 |
| R2 (m, x) | 0.10 | – | – | – | – |
| R2 (y, m, x) | 0.38 | – | – | – | – |
Regression weights a, b, c, and c’ are illustrated in Figure 3. R2 (y, x) is the proportion of variance in y explained by x, R2 (m, x) is the proportion of variance in m explained by x and m. the 95% CI for a × b is obtained by the bias-corrected bootstrap wit 5000 resamples. CP (constructive play) is the independent variable (x), SP (spatial ability) is the mediator (m), and WPS (word problem-solving performance) is the outcome (y). CI (lower = lower bound of 95% confidence interval; CI (upper) = upper bound.