models to explore each explanation, gathering evidence to either support or reject each in turn. They drew liberally on the scientific literature as their understanding and, consequently, their questions, became more complicated. Each student group presented and defended its findings, resulting in a final class consensus about which explanation for moon phases could logically be supported by evidence.
It is reasonable to assume that all of Mr. Gilbert’s students did not begin the unit of study with fully developed inquiry abilities. Knowing that the sequence of learning activities to help students understand moon phases would require them to use all of the inquiry abilities to some degree, Mr. Gilbert decided to take this opportunity to help his students reflect specifically on how one constructs and evaluates explanations from evidence. His goal was to help his students improve these abilities, becoming more independent and skilled in their use and application to learn science content. He introduced the important idea that although models can be helpful to both their learning and to the development of scientific knowledge, every model has its limits. Evaluating and communicating the advantages and disadvantages of the specific models they used in their study of moon phases reinforced this need to be always critical of their tools and methods, and to take those into account when reflecting on what they learned and the confidence they have in that learning, much like scientists do. Further, Mr. Gilbert took advantage of the interesting historical context to broaden his students’ understanding of scientific inquiry and how scientists have used inquiry to advance our scientific knowledge of nature.
Instructional Sequence. The example just given of Mr. Gilbert and his students illustrates a way of sequencing learning and teaching activities that is consistent with the features of inquiry. The unit evolved from data collection, then using those data for concept development and the evaluation of models and explanations. And when students were asked to deal with eclipse frequency, they applied their knowledge to a new scientific challenge. Early in the sequence Mr. Gilbert helped his students become engaged in thinking about moon phases by probing what they thought they knew about the moon and what they wondered about. Their study proceeded through a long period of observation and data gathering during which they recorded and then explored the patterns they observed in the moon’s behavior. Students created their own explanations of the moon’s phases and then tested their explanations and those of other students using models that they could manipulate and continue to explore.