Mary has just completed a grade two content unit on mammals. When asked if a mouse is a mammal, she replies, 'no, because it eats cheese.' Henry reports that “a walking stick is not a mammal because it is a walking stick.” When Joe is asked if a bat is a mammal, he replies, 'yes, because it eats bugs, while he replies that a salamander is not a mammal because, 'it is a fly eater'. These examples point to confusions in young learners understanding of the organizing concepts that underlay scientific classification as mediated through the language of the science text and the questions. It seems that these students cannot apply the essential concepts of their learning. Their responses, clouded with literalism, spurious connections, and contradictions, reveal their attempts to create meaningful thought categories by bridging the known and the unknown.

NAEP scores persistently reveal gaps at grades 4, 8, and 12 in basic understanding of expository texts and a huge failing in students to master higher level thinking evidenced in the abilities to synthesize findings and solve problems with information from expository texts. Dismissing the results as indications of reading problems misses the complexity of issues obscured by the test scores. Contextualizing and grasping the problems, issues, and contradictions associated with science learning and instruction are prerequisites to addressing the content performance gap evident from grades 4 through 12.

While it is tempting to interpret these gaps in knowledge as reading comprehension problems, the real issue centers on cognitive development and expression and language as the motors of knowledge expansion and the role of the teacher in facilitating knowledge making. A project done over the last three years in a rural school in West Virginia has examined the scientific thinking and expression of knowledge of grade two students. This paper examines four questions:

1. Do grade two children have the cognitive tools necessary for scientific thinking?

2. What is the relationship of language to cognitive development and expression of knowledge?

3. If linguistic constructs in texts and discourse inhibit knowledge making and expression, are there ways around these barriers that will enable children to show what they know?

4. What is the role of the teacher in knowledge making learning environments?