We invite you to take part in *CLEF 2023 LongEval: Longitudinal Evaluation of Model Performance shared task.*

*Updated Timelines:* -------------------------------- Deadline for registration: 21st May 2023 Test Data release: 4th May 2023 Submissions Due: 22nd May 2023

*You can now directly register on the Codalab website: * https://codalab.lisn.upsaclay.fr/competitions/12762

*Join the Slack channel*: https://join.slack.com/t/longeval/shared_invite/zt-1tmql633q-w20e3oNq157bkhz...

The CLEF 2023 LongEval lab is motivated by recent research showing that the performance of information retrieval and text classification models drops as the test data becomes more distant in time from the training data.

*LongEval-Classification:* The goal of Task 2 is to propose a temporal persistence classifier which can mitigate performance drop over short and long periods of time compared to a test set from the same time frame as training.

Organisers ------------------------------------------------------------ Rabab Alkhalifa, Iman Bilal, Hsuvas Borkakoty, Jose Camacho-Collados, Romain Deveaud, Alaa El-Ebshihy, Luis Espinosa-Anke, Gabriela Gonzalez-Saez, Petra Galuščáková, Lorraine Goeuriot, Elena Kochkina, Maria Liakata, Daniel Loureiro, Harish Tayyar Madabushi, Philippe Mulhem, Florina Piroi, Martin Popel, Christophe Servan, Arkaitz Zubiaga.