Table 1.
Pretest group means (with SD) and comparisons of participants’ background characteristics and working memory (WM) task performances.
| Control (n = 43) | Interpreting (n = 48) | df | t-value | p-value | |
|---|---|---|---|---|---|
| Background characteristics | |||||
| Interpreting | No | No | |||
| Tested L2 proficiency | 13.79 (3.55) | 12.97 (3.61) | 89 | 1.077 | 0.284 |
| Self-rated L2 proficiency | 19.67 (4.60) | 20.10 (5.74) | 89 | -0.391 | 0.697 |
| Age∗ | 19.86 (0.88) | 19.58 (0.71) | 89 | 1.652 | 0.102 |
| AoA∗ | 9.02 (2.44) | 9.29 (2.28) | 89 | -0.541 | 0.590 |
| Father education∗ | 2.39 (0.69) | 2.75 (1.26) | 89 | -1.632 | 0.106 |
| Mother education∗ | 1.97 (1.01) | 2.16 (1.21) | 89 | -0.808 | 0.421 |
| Intelligence | 67.51 (2.43) | 66.56 (3.25) | 89 | 1.561 | 0.122 |
| WM task performances | |||||
| L2 listening span | 26.20 (7.01) | 26.10 (5.49) | 89 | 0.080 | 0.936 |
| Letter running span | 23.60 (4.18) | 22.38 (5.30) | 89 | 1.218 | 0.226 |
| 2-back: RT | 843.06 (273.11) | 870.92 (265.92) | 89 | -0.493 | 0.623 |
| 2-back: accuracy∗ | 0.85 (0.095) | 0.84 (0.087) | 89 | 0.477 | 0.634 |
∗Data for these variables were not normally distributed, and therefore Mann–Whitney tests were conducted, resulting in the same patterns as shown by independent oxt-test. For Age: U = 844.00, Z = -1.65, p = 0.098; for AoA: U = 986.50, Z = -0.37, p = 0.713; for Father education: U = 910.50, Z = -1.02, p = 0.306; For Mother education: U = 952.00, Z = -0.67, p = 0.506; For 2-back accuracy: U = 955.00, Z = -0.61, p = 0.540.