This volume contains the papers presented at the 18th International Confer-
ence on Algorithmic Learning Theory (ALT 2007), which was held in Sendai
(Japan) during October 1–4, 2007. The main objective of the conference was to
provide an interdisciplinary forum for high-quality talks with a strong theoreti-
cal background and scientific interchange in areas such as query models, on-line
learning, inductive inference, algorithmic forecasting, boosting, support vector
machines, kernel methods, complexity and learning, reinforcement learning, un-
supervised learning and grammatical inference. The conference was co-located
with the Tenth International Conference on Discovery Science (DS 2007).
This volume includes 25 technical contributions that were selected from 50
submissions by the Program Committee. It also contains descriptions of the five
invited talks of ALT and DS; longer versions of the DS papers are available in
the proceedings of DS 2007. These invited talks were presented to the audience
of both conferences in joint sessions.