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Students' ideas on conservation of matter: Effects of expertise and context variables
Author(s) -
Gomez MiguelAngel,
Pozo JuanIgnacio,
Sanz Angeles
Publication year - 1995
Publication title -
science education
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.209
H-Index - 115
eISSN - 1098-237X
pISSN - 0036-8326
DOI - 10.1002/sce.3730790106
Subject(s) - context (archaeology) , mathematics education , categorization , science education , psychology , chemistry , test (biology) , concept learning , task (project management) , context effect , chemistry education , qualitative research , social psychology , epistemology , mathematics , sociology , social science , ecology , engineering , paleontology , philosophy , geometry , systems engineering , enthusiasm , word (group theory) , biology
Recent research on chemistry learning and teaching has described some alternative conceptions held by students as to their understanding of the properties of matter. Several classifications have been proposed to analyze students' conceptions about matter and its changes. Starting from Anderson's categorization, this research studied students' understanding of the qualitative conservation of matter (substance), and how this understanding is influenced by previous instruction in chemistry and task variables. Here, task variables include chemical content and problem context. Four groups of adolescents that differed in age (from 12 to 17 years) and scientific instruction, and two groups of university students with different expertise in chemistry were presented with a 22‐item paper‐and‐pencil test about the conservation of matter. The items involved physical changes (solutions or changes of state) and chemical changes (reactions), and were posed both in academic chemistry contexts and everyday situations. Results show the influence of group membership, task content, and problem context on students' performance. Test scores increased with age and instruction in chemistry, but the influence of chemical expertise was smaller than that predicted from research in other scientific areas. Concerning context, for everyday situations reactions are the most difficult content; on the other hand, in academic chemistry the most difficult content was solutions. Analyses for category answers showed that subjects are likely to concentrate their interpretations in two main categories, interaction (substances interact to form new ones) and modification with identity (substances modified in appearance continue to be the same). However, conceptions depend also significantly on content and context task. Finally, we have found that science instruction increases the consistency of the conceptions held by subjects. Younger subjects and adolescents without scientific instruction tended to be less consistent than more expert subjects. © 1995 John Wiley & Sons, Inc.