ODOC-ELM: Optimal decision outputs compensation-based extreme learning machine for classifying imbalanced data

•The reason of the damage caused by class imbalance for ELM is analyzed in theory.•The influence factors about the performance of ELM on skewed data are investigated.•An optimal decision outputs compensation-based ELM called ODOC-ELM is presented.•Exploring prior data distributions helps improve quality of ELM.•Statistical results indicate the superiority of the proposed ODOC-ELM algorithm.