learned from other sources, was too much water. After their three weeks of work, the class was satisfied that together they had found a reasonable answer to their question. At Mrs. Graham’s suggestion, they wrote a letter to the custodian telling him what they had found. The custodian came to class and thanked them. He said he would change his watering procedure and he did. Mrs. Graham then asked the students how they could find out if their explanation was correct. After some discussion they decided that they would have to wait until next year and see if all the trees got healthy again.

The following year, during the same month that they had observed the discrepancy, all three trees were fully clothed with green leaves. Mrs. Graham’s former students were now even more convinced that what they had concluded was a valid explanation for their observations.

Test explanation


One is struck by the parallels between Mrs. Graham’s class and the inquiring geologist. The geologist began his investigation with a question about an unusual and intriguing observation of nature. So did Mrs. Graham’s children. The scientist then undertook a closer examination of the environment — asked new and more focused questions — and proposed an explanation for what he observed, applying his knowledge of plate tectonics. The children applied their knowledge to formulate several explanations and new questions before undertaking further investigations. The scientist, knowing of investigations by other scientists, used their findings to confirm the validity of his original explanation. In Mrs. Graham’s class, groups whose explanations were not confirmed lent strength to the “excess water” explanation. The geologist published his findings. The children “published” their findings in their reports to their classmates and later in a letter to the custodian. Although scientific research does not always influence public policy, the geologist’s discoveries resulted in building code revisions in Washington and Oregon. The children’s investigations led to revised lawn watering procedures at their school.

Inquiry in the classroom can take many forms. Investigations can be highly structured by the teacher so that students proceed toward known outcomes, such as discovering regularities in the movement of pendulums (as noted in the Foreword and in the classroom vignette on pages 146-147 of the National Science Education Standards). Or investigations can be free-ranging explorations of unexplained phenomena, like the tree leaf discrepancies in Mrs. Graham’s schoolyard. The form that inquiry

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