@techreport { sequeira12, institution = {GAIPS - INESC-ID}, keywords = {Reinforcement Learning;Affective Computing;}, month = {March}, number = {GAIPS-TR-001-12}, title = {Learning by Appraising: An emotion-based approach for intrinsic reward design}, type = {GAIPS tech. rep. series}, year = {2012}, author = {Pedro Sequeira and Francisco S. Melo and Ana Paiva} }