Improving the Efficiency of Ensemble Classifier Adaptive Random Forest with Meta Level Learning for Real-Time Data Streams Monika Arya and Chaitali Choudhary Abstract New challenges have emerged in data mining as the traditional techniques have floundered with real-time data streams. The traditional technique needs refur- bishing so as to acclimatize with concept drifting data streams. Thus dealing with the concept changes is the most imperative task of stream data mining. Ensemble classi- fiers have the ability to automatically adapt with the incoming drifts and, therefore, it is the most interesting research area in data stream mining. Bagging, Boosting and Random forest generation are the common ensemble techniques and are the most popular machine learning approaches in the current scenario for static data (Gomes HM, Bifet A, Read J, Barddal JP, Enembreck F, Pfharinger B, Abdessalem T (2017) Adaptive random forests for evolving data stream classification. Mach Learn 106(9– 10):469–1495, [1]). A large number of base classifiers in an ensemble can cause computational overhead. Data mining classifiers for real-time data streams, there- fore, need to be updated constantly and retrained with the labeled instances of the newly arrived novel classes in data streams and to cope with concept drift; otherwise, the mining models will become less and less accurate as time passes by. However, for data streams, adaptive random forest algorithms have been widely used for ensem- ble generation due to its competence to handle different types of drifts. This paper proposes a modified adaptive random forest with meta level learner algorithm and concept adaptive very fast decision tree to overcome the concept drift problem in real-time data streams. The proposed algorithm is experimentally compared with state-of-the-art adaptive random forest algorithm on several real synthetic datasets. Results indicate its efficiency in terms of accuracy and processing time. Keywords Data stream mining · Random forests · Ensemble · Concept drift · Pruning · Forest · Adaptive random forest · Data streams M. Arya · C. Choudhary (B ) University of Petroleum and Energy Studies, Dehradun, India e-mail: chaitali.choudhary@gmail.com M. Arya e-mail: arya.akshara@gmail.com © Springer Nature Singapore Pte Ltd. 2020 V. Bhateja et al. (eds.), Intelligent Computing and Communication, Advances in Intelligent Systems and Computing 1034, https://doi.org/10.1007/978-981-15-1084-7_2 11