Research Article

Adaptive Online Sequential ELM for Concept Drift Tackling

Table 2

Data set dimension, quantity, evaluation method, and performance measurement.
(a) Data set dimension and quantity

Data set ConceptsInputsOutputsQuantity (×concepts)

SEA 43220000 (×4)
STAGGER 3924400 (×3)
MNIST 2784, 8651070000 (×2)
USPS 18653648908 (×1)

(b) Evaluation method

Data set Evaluation methodTrainingTesting

SEA 5-fold cross-validation16000 (×4)4000 (×4)
STAGGER 5-fold cross-validation3520 (×3)880 (×3)
MNIST Holdout (10x trials)60000 (×2)10000 (×2)
USPS Holdout (10x trials)3505013858

(c) Performance measurements

Measure Specification

Accuracy The accuracy of classification in % from
Predictive accuracy The accuracy measurement of the future sequential training data [20]
Testing accuracy The accuracy measurement of the testing data set excluded from the training
Forgetting capability The testing accuracy differences between the current concept with the previous concepts
Cohen’s kappa and kappa error The statistic measurement of interrater agreement for categorical items