Table 3.
The eight predictor variables selected for the Typability Index
| Predictor | Theme(s) | β | B | SE B | t | p |
|---|---|---|---|---|---|---|
| Proportion of lowercase non-space characters | L, FoU | 0.533 | 4.694 | 0.207 | 22.68 | <.001 |
| Total keystrokes | TP | –0.433 | –0.012 | < 0.001 | –22.34 | <.001 |
| Syllables per word | TP | –0.300 | –0.431 | 0.028 | –15.22 | <.001 |
| Proportion of words within high-frequency words | TP, FoU | 0.266 | 0.693 | 0.052 | 13.35 | <.001 |
| Proportion of symbol non-space characters | L, FoU | –0.220 | –4.037 | 0.433 | –9.32 | <.001 |
| Bigram frequency | FoU | 0.192 | < 0.001 | < 0.001 | 12.49 | <.001 |
| Proportion of characters within non-words | TP, FoU | –0.157 | –1.665 | 0.163 | –10.23 | <.001 |
| Proportion of right-side keys | L, B | 0.100 | 0.462 | 0.076 | 6.08 | <.001 |
| (Intercept) | –4.022 | 0.193 | –20.89 | <.001 |
Themes, as described above Table 1, are Text processing (TP), Frequency of use (FoU), Layout (L), and Biomechanical (B). β represents the standardised beta coefficient, while B denotes the unstandardised beta coefficient and SE is standard error. Positive β and B values represent typing ease (faster than one’s own average) while negative values suggest difficulty (slower than average)