Inventory of 67 computed features for writing and drawing
| Feature type (units) | Feature abbreviation | Feature description | Feature dimension |
| Static features | |||
| Dimensional (mm) | avgStrLenAir, medStrLenAir, maxStrLenAir, minStrLenAir, stdStrLenAir, iqrStrLenAir, avgStrLen, medStrLen, maxStrLen, minStrLen, stdStrLen, iqrStrLen | Average, median, maximum, minimum, SD and IQR of pen stroke length in air and on tablet surface. | 6×2=12 |
| Temporal (s) | inAirT, onSurT, totalT, ratioAirtoSurT, satPreDur, noPause | Time in air; time on tablet surface; total time; ratio of air-to-surface time; duration with saturated pressure; number of pauses. | 6 |
| Kinematic features | |||
| Velocity (mm⋅s−1) | avgVx, medVx, maxVx, stdVx, avgVy, medVy, maxVy, stdVy, ratioVxVy | Average, median, maximum and SD of pen tip velocity in x and y directions; ratio of pen tip median velocity in x and y. | 4×2+1=9 |
| Acceleration (mm⋅s−2) | avgAx, medAx, maxAx, stdAx, avgAy, medAy, maxAy, stdAy, ratioAxAy | Average, median, maximum and SD of pen tip acceleration in x and y directions; ratio of median acceleration in x and y. | 4×2+1=9 |
| Jerkiness (mm⋅s−3) | avgJx, medJx, maxJx, stdJx, avgJy, medJy, maxJy, stdJy, ratioJxJy | Average, median, maximum and SD of pen tip jerk in x and y directions; ratio of median jerk in x and y. | 4×2+1=9 |
| Linear speed (mm⋅s−1) | avgS, medS, maxS, stdS | Average, median, maximum and SD of pen tip speed. | 4 |
| Angular speed (rad⋅s−1) | avgAngS, medAngS, maxAngS, stdAngS | Average, median, maximum and SD of pen tip angular speed. | 4 |
| Direction changes | Dx, Dy, Dxy, diffDxy | Total number of direction changes in x direction, y direction and both x and y directions; absolute differences in direction changes in either x or y. | 4 |
| Pen pressure features | |||
| Pressure | avgP, medP, stdP, skewP, kurtP | Average, median and SD of pen tip pressure applied on the tablet surface; skewness and kurtosis of pressure. | 5 |
| Pressure differences | avgDiffP, medDiffP, stdDiffP, skewDiffP, kurtDiffP | Average, median and SD of pen tip pressure difference applied on the tablet surface; skewness and kurtosis of pressure difference. | 5 |