摘要：AbstractLanguage is essential in doing science and shapes the construction and communication of scientific ideas. The language of science is an integration of texts, visual images (i.e. diagrams, pictures, graphs, maps, tables, charts) and mathematical expressions (i.e. equations). Learning and teaching science means also learning and teaching the media of science communication. This study aims at comparing visual material included in PISA science test items related to biological systems and in assessment tasks in Biology school textbooks intended for 7th and 9th grade students in Greece.Specifically, the following dimensions of the visual material were analyzed:–The frequency of its inclusion in PISA and textbook items–Its type (e.g. photographs, diagrams, tables)–Its role within items, ranging from visual images functioning as concrete representations of verbal descriptions displaying redundant information to the relevant questions, to graphics providing partial information that is necessary, but not sufficient, for answering the questions, and to images containing all information that the test taker needs for answering the questions–The format of the required answers (i.e. completion of graphs, or tables, visual cues, free graphical response, verbal or numerical response)The results reveal tensions between visual images comprised in PISA and textbook assessment items according to the aforementioned dimensions. This indicates that Greek student's limited familiarity with the types and function of visual material used by PISA could be a possible factor –among others– for interpreting their low achievement in the PISA survey
关键词：Assessment tasks;Biology;PISA;school textbooks;visual material
