Pupils’ understanding of photosynthesis: A questionnaire for the simultaneous assessment of all aspects

In this study, a close-ended questionnaire examining all aspects of photosynthesis simultaneously has been developed and administered to 290 Greek pupils aged 13. It contains complementary or logically related items that permitted us to assess the understanding of each aspect by carrying out cross-analysis. The main findings are: that pupils are not able to conceive photosynthesis as a chemical reaction and they do not appreciate the role of chlorophyll, that pupils’ misunderstanding of the energy concept concerns the form of energy required as well as the notion of harnessing the sun’s energy, that some pupils hold the misconception that plants receive all their nutrients from the environment, and that pupils confuse photosynthesis with respiration and also believe that respiration occurs when there is no photosynthesis. This questionnaire could be used by teachers for the assessment of their pupils’ understanding of each individual aspect of photosynthesis and of the simultaneous understanding of more than one aspect. © 2006 Taylor & Francis

Exploring Undergraduates' Understanding of Photosynthesis Using Diagnostic Question Clusters

We present a diagnostic question cluster (DQC) that assesses undergraduates' thinking about photosynthesis. This assessment tool is not designed to identify individual misconceptions. Rather, it is focused on students' abilities to apply basic concepts about photosynthesis by reasoning with a coordinated set of practices based on a few scientific principles: conservation of matter, conservation of energy, and the hierarchical nature of biological systems. Data on students' responses to the cluster items and uses of some of the questions in multiple-choice, multiple-true/false, and essay formats are compared. A cross-over study indicates that the multiple-true/false format shows promise as a machine-gradable format that identifies students who have a mixture of accurate and inaccurate ideas. In addition, interviews with students about their choices on three multiple-choice questions reveal the fragility of students' understanding. Collectively, the data show that many undergraduates lack both a basic understanding of the role of photosynthesis in plant metabolism and the ability to reason with scientific principles when learning new content. Implications for instruction are discussed