Table 2.
Coefficients for Paths a, Paths b, and Paths c1 in Mediation Models
| Path | Coefficient (SE) | t-Value | p-Value |
|---|---|---|---|
| Path b: Effect of Grade 2 Skills on Grade 4 Fractions Concepts | |||
| Number line estimation → Fraction concepts | −083 (.04) | −1.98 | .050 |
| Arithmetic computations → Fraction concepts | .206 (.09) | 2.35 | .020 |
| Path a: Effect of Grade 1 Predictor on Grade 2 Skill | |||
| Nonverbal reasoning → Number line estimation | .061 (.11) | 0.56 | .578 |
| Nonverbal reasoning → Arithmetic computations | .008 (.05) | 0.15 | .884 |
| Language ability → Number line estimation | −1.675 (.62) | −2.69 | .008 |
| Language ability → Arithmetic computations | .600 (.30) | 2.00 | .047 |
| Attentive behavior → Number line estimation | .047 (.05) | 0.97 | .336 |
| Attentive behavior → Arithmetic computations | .054 (.02) | 2.33 | .021 |
| Executive control → Number line estimation | .207 (.16) | 1.31 | .193 |
| Executive control → Arithmetic computations | .021 (.08) | 0.27 | .787 |
| Visual-spatial memory → Number line estimation. | − 340 (.16) | −2.17 | .032 |
| Visual-spatial memory → Arithmetic computations | .019 (.08) | 1.44 | .153 |
| Number knowledge → Number line estimation | − 581 (.61) | −0.95 | .344 |
| Number knowledge → Arithmetic computations | .313 (.29) | 1.06 | .290 |
| Path c1: Direct Effect of Grade 1 Predictor on Grade 4 Fraction Concepts | |||
| Nonverbal reasoning → Fractions Concepts | .071 (.06) | 1.29 | .200 |
| Language ability → Fractions Concepts | .218 (.32) | 0.67 | .503 |
| Attentive behavior → Fractions Concepts | .025 (.02) | 1.01 | .315 |
| Executive control → Fractions Concepts | − 052 (.08) | −0.64 | .521 |
| Visual-spatial memory → Fractions Concepts | −006 (.08) | −0.07 | .943 |
| Number knowledge → Fractions Concepts | 1.128 (.31) | 3.63 | .000 |
Note. In all models, the effects of the other first grade predictor variables were controlled, as were the effects of grade 1 reading and math ability, racial/ethnic and subsidized lunch status.