Acknowledgment to Reviewers of Machine Learning and Knowledge Extraction in 2021

Rigorous peer-reviews are the basis of high-quality academic publishing. Thanks to the great efforts of our reviewers, Machine Learning and Knowledge Extraction was able to maintain its standards for the high quality of its published papers. Thanks to the contribution of our reviewers, in 2021, the median time to first decision was 19 days and the median time to publication was 42 days. The editors would like to extend their gratitude and recognition to the following reviewers for their precious time and dedication, regardless of whether the papers they reviewed were finally published:

Abubakar, Aliyu	Mahmoud, Karar
Ambrosino, Fabrizio	Marchand, Cédric
Arteta, Alberto	Marcińczuk, Michał
Artiemjew, Piotr	Martínez-Otzeta, José María
Bigand, Andre	Matetic, Maja
Borza, Diana	Matrenin, Pavel
Bozkurt, Aras	Mezzini, Mauro
Brandusoiu, Ionut	Milicevic, Mario
Byeon, Haewon	Mohammed, Bashir
Cabada, Joaquin Gayoso	Moraru, Luminita
Carrington, André M.	Moya-Albor, Ernesto
Castillo Olea, Cristian	Mrówczyńska, Maria
Chalmeta, Ricardo	Muncharaz, Javier Oliver
Chen, Liang-Bi	Naqvi, Rizwan Ali
Choi, Minseok	Nayak, Sridhara
Conflitti, Paolo	Nayel, Hamada A.
Crisan, Gloria Cerasela	Ojeda, Dora Luz
Damaševičius, Robertas	Panek, Jarosław
Delnevo, Giovanni	Pejic Bach, Mirjana
Demertzis, Konstantinos	Piga, Dario
Deriu, Marco Agostino	Podda, Marco
Derlatka, Marcin	Pouliakis, Abraham
Dowling, Benjamin	Radac, Mircea-Bogdan
Egger, Jan	Rana, Pratip
Fakotakis, Nikos	Riguzzi, Fabrizio
Feng, Chaochao	Rossi, Riccardo
Garcke, Jochen	Saeed, Khalid
Gomes, Rahul	Samakovitis, Georgios
Gornicki, Krzysztof	Schreiber, Andreas
Gosti, Giorgio	Sciuto, Grazia Lo
Howe, Bill	Seeland, Marco
Hsin, Kun-Yi	Shan, Hongming
Jeong, Young-Seob	Shi, Feng Bill
Jurman, Giuseppe	Temerinac-Ott, Maja
Kanavos, Andreas	Tran, Minh-Quang
Kapociute-Dzikiene, Jurgita	Trujillo, Logan T.
Kertész, Gábor	Tsaramirsis, George
Kieseberg, Peter	Turkay, Cagatay
Kiourt, Chairi	Valero-Mas, Jose J.
Klimaszewski, Krzysztof	Veloso, Bruno Miguel
Klimova, Alexandra	Wang, Hsiang-Chen
Le, Nguyen-Thinh	Wang, Kai
Leo, Marco	Wood, David
Li, Guanpeng	Xu, Hongming
Lin, Guo-Shiang	Yazdani, Maziar
Lisjak, Dragutin	Yoo, Jung Sun
López-Yáñez, Itzamá	Zaborowicz, Maciej
Luk, Robert	Zambrano-Martinez, Jorge Luis