CohMetrix Model 2b Variable Importance - shmercer/writeAlizer GitHub Wiki
Ensemble Weightings and Metric Importance
Coh-Metrix Model 2b
This model used Coh-Metrix scores from 7 min narrative writing samples ("I once had a magic pencil and ...") from 131 students in the winter of Grades 2-5 (Mercer et al., 2019) to predict holistic writing quality on the samples (elo ratings calculated from paired comparisons).
Highly correlated Coh-Metrix metrics (r > |.90|) were excluded during pre-processing (see section on Scoring Model Development for more details).
Mercer, S. H., Keller-Margulis, M. A., Faith, E. L., Reid, E. K., & Ochs, S. (2019). The potential for automated text evaluation to improve the technical adequacy of written expression curriculum-based measurement. Learning Disability Quarterly, 42, 117-128. https://doi.org/10.1177/0731948718803296
Algorithm Weightings in Ensemble
Abbreviations:
- all = ensemble model
- mars = bagged multivariate adaptive regression splines
- gbm = stochastic gradient boosted trees
- svm = support vector machines
- cube = cubist regression
The table below presents the linear weightings of each algorithm for the ensemble model.
Intercept | mars | gbm | svm | cube |
---|---|---|---|---|
-7.2585 | 0.2289 | 0.5300 | 0.1527 | 0.1150 |
Metric Importance in Each Algorithm and Ensemble
Each column sums to 100 (so values can be interpreted as % contribution to the model).
Detailed information on Coh-Metrix abbreviations and indices is available here.
Metric | overall | mars | gbm | svm | cube |
---|---|---|---|---|---|
DESWC | 30.39 | 45.46 | 34.5 | 4.37 | 16.04 |
LSAGN | 7.18 | 0 | 9.31 | 2.85 | 17.43 |
DESWLlt | 6.73 | 19 | 2.42 | 1.37 | 9.31 |
LDMTLD | 5.59 | 0 | 8.91 | 2.47 | 5.54 |
SYNLE | 5.43 | 13.58 | 3.65 | 1.79 | 2.18 |
WRDIMGc | 3.6 | 9.36 | 1.84 | 1.22 | 3.37 |
WRDNOUN | 3.19 | 6.64 | 1.38 | 1.77 | 6.53 |
CNCAdd | 1.87 | 5.96 | 0.45 | 1.02 | 1.39 |
WRDVERB | 1.42 | 0 | 2.02 | 1.67 | 1.19 |
SMCAUSwn | 1.25 | 0 | 1.83 | 2.04 | 0 |
DESWLltd | 1.16 | 0 | 1.21 | 1.53 | 2.77 |
CRFCWO1d | 1.09 | 0 | 1.18 | 2.17 | 1.39 |
WRDHYPnv | 1.02 | 0 | 0.98 | 1.36 | 2.77 |
CRFNOa | 0.99 | 0 | 1.37 | 1.9 | 0 |
RDFRE | 0.99 | 0 | 1.54 | 0.25 | 1.39 |
LSAGNd | 0.85 | 0 | 0.53 | 1.76 | 2.77 |
DESWLsy | 0.77 | 0 | 1.11 | 1.28 | 0 |
SYNMEDpos | 0.76 | 0 | 0.29 | 2 | 2.77 |
WRDPRP3s | 0.74 | 0 | 0.91 | 1.53 | 0.4 |
DESPL | 0.73 | 0 | 0.44 | 2.34 | 1.39 |
CNCAll | 0.72 | 0 | 0.44 | 0.96 | 3.17 |
RDL2 | 0.71 | 0 | 0.6 | 1.65 | 1.39 |
PCCNCz | 0.71 | 0 | 0.62 | 1.6 | 1.39 |
PCVERBz | 0.69 | 0 | 0.82 | 1.78 | 0 |
WRDPRO | 0.69 | 0 | 0.69 | 1.18 | 1.39 |
CNCTemp | 0.65 | 0 | 0.71 | 1.87 | 0 |
WRDFRQc | 0.65 | 0 | 0.98 | 0.99 | 0 |
WRDFRQmc | 0.63 | 0 | 0.56 | 1.25 | 1.39 |
DRVP | 0.62 | 0 | 0.93 | 0.92 | 0 |
LSASS1d | 0.61 | 0 | 0.65 | 1.87 | 0 |
SMCAUSlsa | 0.6 | 0 | 0.94 | 0.77 | 0 |
CRFCWOad | 0.6 | 0 | 0.61 | 1.92 | 0 |
WRDMEAc | 0.59 | 0 | 0.53 | 1.4 | 0.99 |
PCTEMPp | 0.56 | 0 | 0.78 | 1.02 | 0 |
SMCAUSv | 0.56 | 0 | 0.85 | 0.83 | 0 |
PCCNCp | 0.56 | 0 | 0.02 | 1.62 | 2.77 |
WRDFRQa | 0.53 | 0 | 0.73 | 1.01 | 0 |
LSASSp | 0.53 | 0 | 0.54 | 1.71 | 0 |
LDTTRc | 0.52 | 0 | 0.64 | 1.3 | 0 |
DRPP | 0.51 | 0 | 0.7 | 1.02 | 0 |
PCREFp | 0.5 | 0 | 0 | 0.7 | 3.56 |
CRFCWO1 | 0.47 | 0 | 0.4 | 1.75 | 0 |
SMCAUSvp | 0.46 | 0 | 0.47 | 1.42 | 0 |
PCNARz | 0.45 | 0 | 0.26 | 1.64 | 0.59 |
SYNNP | 0.45 | 0 | 0.3 | 0.91 | 1.39 |
PCSYNz | 0.45 | 0 | 0.32 | 0.87 | 1.39 |
SMINTEp | 0.45 | 0 | 0.4 | 1.66 | 0 |
LDTTRa | 0.43 | 0 | 0.23 | 1.06 | 1.39 |
DESWLsyd | 0.42 | 0 | 0.35 | 1.62 | 0 |
CRFANPa | 0.41 | 0 | 0.34 | 1.59 | 0 |
SMINTEr | 0.41 | 0 | 0.6 | 0.69 | 0 |
CNCLogic | 0.4 | 0 | 0.51 | 0.89 | 0 |
WRDAOAc | 0.4 | 0 | 0.58 | 0.69 | 0 |
WRDHYPv | 0.4 | 0 | 0.36 | 1.45 | 0 |
CNCNeg | 0.4 | 0 | 0.32 | 1.17 | 0.59 |
CNCCaus | 0.38 | 0 | 0.47 | 0.92 | 0 |
WRDFAMc | 0.37 | 0 | 0.46 | 0.91 | 0 |
SYNSTRUTa | 0.36 | 0 | 0.36 | 1.2 | 0 |
CRFAOa | 0.35 | 0 | 0.19 | 1.68 | 0 |
WRDADV | 0.34 | 0 | 0.32 | 1.19 | 0 |
SMCAUSr | 0.33 | 0 | 0.61 | 0.1 | 0 |
DESSLd | 0.32 | 0 | 0.18 | 1.5 | 0 |
PCCONNp | 0.29 | 0 | 0.46 | 0.37 | 0 |
WRDPOLc | 0.28 | 0 | 0.28 | 0.93 | 0 |
WRDADJ | 0.28 | 0 | 0.4 | 0.51 | 0 |
DRAP | 0.26 | 0 | 0.24 | 0.87 | 0 |
DRNP | 0.26 | 0 | 0.33 | 0.57 | 0 |
WRDHYPn | 0.26 | 0 | 0.27 | 0.84 | 0 |
CNCTempx | 0.25 | 0 | 0.23 | 0.86 | 0 |
DRNEG | 0.23 | 0 | 0.13 | 1.08 | 0 |
PCREFz | 0.23 | 0 | 0.24 | 0.7 | 0 |
PCVERBp | 0.22 | 0 | 0 | 1.48 | 0 |
PCNARp | 0.2 | 0 | 0.01 | 1.35 | 0 |
PCDCp | 0.19 | 0 | 0.11 | 0.9 | 0 |
PCSYNp | 0.09 | 0 | 0.02 | 0.56 | 0 |
WRDPRP3p | 0 | 0 | 0 | 0 | 0 |