An understanding of the concepts of atom and molecule is fundamental to the learning of chemistry. Any misconceptions and alternative conceptions that students harbor about these concepts will impede further learning. This article identifies misconceptions related to the fundamental characteristics of atoms and molecules which Grade‐12 students hold. Data were obtained by administration of semistructured interviews to a stratified, random sample of 30 students of differing abilities and backgrounds in science. Fifty‐two misconceptions were observed and are reported. These are grouped into 11 categories. Six relate to the structure, composition, size, shape, weight, bonding, and energy of molecules; five relate to the structure, shape, size, weight, and animistic perceptions of atoms. Some of the misconceptions identified parallel the historical development of scientific concepts.

Developing an understanding of the nature of food webs is an important topic in today's biology curricula. The relationships represented in a food web are rule-like in nature. Hence, it should be possible to construct a learning hierarchy for this concept. A hierarchy leading to the ability to determine how a change in the size of one population can affect another population in the same web but not on the same chain was hypothesized. Data from 200 subjects were extremely consistent with the hierarchy. A second major focus related to the identification of specific misconceptions held by subjects for food webs. The need to identify students' misconceptions of important concepts has been expressed widely in the recent science education literature. In the present article, an argument is presented for the usefulness of learning hierarchies in this work. Specific misconceptions and the frequencies of their Occurrence are reported.

No abstract

During the last two decades, massive efforts have been directed at uncovering different science concepts held by school age students. This particular study focused on identifying high school students' views regarding the nature of science. Thirty‐two students were chosen from each of the following three countries: Canada, the United States, and Australia. Interviews were conducted with each student. The interview protocol contained the same core questions with an opportunity built in to allow both the student and the interviewer to seek clarification and extension as necessary. All of the interviews were audiotape recorded and transcribed. Some major differences and many commonalities were observed among the three groups of students. These results should be potentially useful to a wide range of science educators and curriculum developers in that one's ability to become scientifically literate is greatly impair ed when the nature of science is not completely understood.