Skill Classification and Behavioral Analysis of Excavator Operators Using Wearable Sensors
94.5% mean balanced accuracy
Research summary
94.5% mean balanced accuracy from wearable joystick signals.
Research record
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Evaluation results, cohort definitions, limitations, and source locators are maintained in the related project. This record does not duplicate the project metrics.
Selected finding
The headline result from the related case study, with its sample and source.
Usable IMU trials
36 trials. 19 experienced, 17 inexperienced; wearable classification and coordination branch.
Mean balanced accuracy, repeated five-fold validation
Reported in sourceHighest reported value: Logistic regression, 94.5%. Whiskers show one standard deviation, not a confidence interval.
A whisker reaches beyond the scale and is drawn to the axis edge without an end cap. The data table gives the exact value.
Data table
| Condition | Value | Uncertainty |
|---|---|---|
| Logistic regression | 94.5% | SD 9.0 percentage points |
| Linear discriminant analysis | 92.5% | SD 11.6 percentage points |
| Radial-basis SVM | 92.2% | SD 10.7 percentage points |
| Random forest | 89.0% | SD 12.2 percentage points |
Denominator: Usable 36-trial IMU sample; twenty repeats of stratified five-fold cross-validation.
Adapted from Skill Classification and Behavioral Analysis of Excavator Operators Using Wearable Sensors, Table 4; Section 4.2.1; Figure 6; Table 5.
Evaluation Scope & Methodology
Samples, denominators, uncertainty, sources and limits
Approach
Repeated stratified five-fold cross-validation with twenty repeats and training-fold preprocessing; separate corrected gaze comparisons.
Results and scope belong to the related case study, Measuring excavator operator behavior.
Cohorts and samples
| Cohort | Sample | Definition |
|---|---|---|
| Usable IMU trials | 36 trials | 19 experienced, 17 inexperienced; wearable classification and coordination branch. |
| Separate gaze analysis | 40 participants | Gaze/head comparisons; not the IMU classifier cohort. |
Reported measures
| Measure | Unit | Cohort | Denominator | Uncertainty | Evidence |
|---|---|---|---|---|---|
| Mean balanced accuracy, repeated five-fold validation | Percent | Usable IMU trials | Usable 36-trial IMU sample; twenty repeats of stratified five-fold cross-validation | Logistic regression: SD 9.0 percentage points; Linear discriminant analysis: SD 11.6 percentage points; Radial-basis SVM: SD 10.7 percentage points; Random forest: SD 12.2 percentage points | Reported in source |
| Mean simultaneous joystick movement | Percent | Usable IMU trials | Both-active time as a share of active time; reported group means | None reported | Reported in source |
| Median pupil variability | Millimetres | Separate gaze analysis | Separate gaze analysis; reported experience-group medians | None reported | Reported in source |
| Cliff's delta: experienced versus inexperienced | Cliff's delta from −1 to 1 | Separate gaze analysis | 40 participants, 20 per group; q values Benjamini-Hochberg corrected across all 16 eligible metrics | Pupil variability: 95% CI [−1.00, −0.69]; Mean saccade amplitude: 95% CI [−1.00, −0.65]; Vertical gaze spread: 95% CI [−0.96, −0.55]; Mean saccade duration: 95% CI [−0.94, −0.37]; Stationary gaze entropy: 95% CI [−0.91, −0.41]; Head rotation rate: 95% CI [−0.89, −0.38]; Median fixation duration: 95% CI [−0.76, −0.17]; 2D gaze dispersion: 95% CI [−0.73, −0.10] | Reported in source |
Uncertainty definitions
- SD. Standard deviation as reported by the source. It describes spread across evaluation folds or runs. It is not a confidence interval.
- 95% CI. 95% confidence interval as reported by the source.
Protocol
- Keep the N=36 IMU and N=40 gaze branches separate.
- Classifier uncertainty is fold standard deviation, not a confidence interval.
- Leave-one-out accuracy belongs to a separate validation condition.
Limitations
- One simulator and task with a small sample.
- The gaze sample is separate from the usable IMU sample.
- No combined IMU–gaze classifier result or independent field validation is established.
- Descriptive group differences are not validated training targets.
- Pupil variability alone does not establish cognitive load.
Sources
- Skill Classification and Behavioral Analysis of Excavator Operators Using Wearable Sensors, Table 4; Section 4.2.1; Figure 6; Table 5 (Supplied manuscript reviewed November 2026). Public release pending
Cite this record
Asif Faisal Chowdhury, Muhammad Tahir Khan, Chao Wang. Skill Classification and Behavioral Analysis of Excavator Operators Using Wearable Sensors. Manuscript.
Formatted from the supplied manuscript. Publisher metadata has not been verified, so no BibTeX is offered yet.