@inbook { pereira14, chapter = {Social Presence and Artificial Opponents}, edition = {Adrian David Cheok, Anton Nijholt and Teresa Romão}, keywords = {Social Robotic Companions;Computer Games;Affective Computing;Intelligent Virtual Agents;}, month = {August}, pages = {115-135}, publisher = {Springer}, series = {Human–Computer Interaction Series}, title = {Entertaining the Whole World}, year = {2014}, author = {André Pereira and Rui Prada and Ana Paiva} }