Asia-Pacific Forum on Science Learning and Teaching, Volume 5, Issue 3, Article 8 (Dec., 2004)
Yeung Chung LEE and Pun Hon NG
Hong Kong primary pupils' cognitive understanding and reasoning in conducting science investigation: A pilot study on the topic of "Keeping Warm"
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Scientific investigations and their demand on cognitive understanding and reasoning

Investigations can be characterized as problem-solving activities involving the use of science processes including formulating hypotheses, making predictions, designing experiments, observing, measuring, analyzing data and evaluating methods (Watson and Wood-Robinson 1998). Shulman and Keislar (1966, cited in Etheredge and Rudnitsky, 2003, p 10) described scientific inquiry in form of a four-step model which involves problem sensing, problem formulation, searching and information gathering and problem resolving. The Assessment of Performance Unit (APU) of the U.K. adopted a more refined model which sees investigation as a number of systematic progressive steps including: problem identification, reformulation of testable question, planning the investigation, conducting the investigation, recording data, interpreting data, and drawing conclusions, evaluation of methods and results which leads to further formulation of problems, or change in design or technique before students come up with a solution to the problem (Gott and Murphy 1987).

Millar, et al (1994) devised another model in their Procedural and Conceptual Knowledge in Science Project (PACKS) on the basis of the APU model. The PACKS model was formulated from results of observation of groups of 9 to 14 years old students performing investigation. It depicts investigation as a five-stage process which resembles the APU model to a certain extent. The five stages are: given task, task-as-interpreted, a set of observations or measurements, a stated conclusion, and evaluative comments on the conclusion(s) (Millar 1994, p.222) The model further describes the kinds of knowledge students are required to draw on to tackle the problem-solving task. Such knowledge consists of declarative knowledge of science concepts and procedural knowledge of scientific investigating. To explain these two types of knowledge in terms of the five-stage model, the declarative knowledge is students' understanding of the science knowledge relevant to the task so that students could formulate suitable hypotheses or know what to observe. Procedural understanding refers to three aspects essential to the problem-solving process. The first aspect is the understanding of the nature and purpose of the task, that is, whether or how far students can identify with the purpose of the task as a scientific investigation carrying with it the notions of fair test, etc. The second aspect is the ability to carry out relevant manipulative skills so that measurements could be taken and data presented. The third part is seen to be crucial. It is the understanding of criteria for evaluating the quality of empirical evidence, also known as concepts of evidence, which informs different stages ranging from designing experiments, controlling variables, choosing sufficient values for measurement, judging the reliability of data, drawing appropriate conclusions, to evaluating methods and results of the investigation. The concepts of evidence were further elaborated by Gott, et al (2003) to include detailed steps or criteria such as sample size and method of data presentation to ensure reliability and validity of the design. They argued that some students would pick up these ideas in the course of studying science through a traditional approach, but many would not do so unless they were specifically taught. It is this kind of understanding that we believe are important to inform curriculum planners and teachers in designing curriculum and instructional strategies that promote inquiry.


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