Abstract: Definition of the words “argument” and “counterargument” in a case study research with 91 Greek students of 5th and 6th grade present children’s prior knowledge on argumentation and persuasive writing. This study is a part of broader research concerning teaching experimental strategies of an intervention program in Greek public schools with teaching and learning persuasive language, and meaning making in a writing class. The authors discuss the results of this study in evaluation of a questionnaire’s data. The data confirm the existence of cognitive, meta-cognitive and meta-linguistic limitations in their intervention: Children’s pre-existing understanding of concepts and terms, such as “argument”, “counterargument”, “fallacy”, etc., is limited, if not absent. Findings on students’ limited declarative knowledge in defining what an “argument” or a “counterargument” is, indicate the need of a systematic and effective integration of arguments and especially this of counterarguments, as procedural knowledge in teaching argumentative writing with children at the age of 10-12 years.
Key words: definition; argument; counterargument; teaching; writing