edited by TOM TIPTON
learning activitief
University of Nebraska Lincoin. NE 68508
A Classroom Learning Cycle: Using Diagrams to Classify Matter Helen J. James Weber State College Ogden. VT 84408
Samuel L. Nelson Norm Bend Bentral Jr.-sr. High Schwl North Bend. NE 68649 T h e first few lectures in a beginning chemistry class are often frustrating for both students and instructors. Terms such as "atom." "compound," and "chemical chances" are intn,duwd. Since the siudrnts have not handled or elen swn the partides i n w h d , the" h.~ve.diftict~lr\~ undersr:lndinp tlw terms. Piaget's theory of cognitive development (1-4) offers an explanation for these difficulties. Piaget classifies students as "concrete operational" or "formal operational." If their reasoning is concrete operational, the studehts can deal most effectively with concrete objects and materials, and familiar experiences. On the other hand, formal operational students can reason using abstract concepts. However, even formal o~erationalindividuals often revert to concrete o~erational thought upon encountering a new situation. Learnine cvcles have been develo~edto hridee the ean hetween ~iaget's theory and classroo& activities"(5) an-d d'have been described for a chemistrv lahoratorv" aroeram . " (6. . . 7). . A learning cycle involves the active participation of the students in exploration. invention. and a~vlication ahases. Durine the .. exploration phase, students are provided kith opportunities to explore experiences relevant to a new concept. For instance, they may have hands-on experiences, an opportunity to sort or classifv examoles, or an exercise reauirine recall of related experiences. l ' h c activitie~are desiin6.d t i help iocus the studrnrs' artenrim un the rimceut an11nil1 ofwn lead them t o question previously acquired knowledge. After the exploration, the students should he readv to compare information and organize data. During this invention phase the instructor will usually lead a discussion in which necessary terminology is provided. The concept being studied is also generated, primarily from student input, if possible. The application phase allows the students to use the new concept in a novel way that helps them to generalize the concept and broadens their understanding of it. The authors have developed learning cycles for use in the classroom. One cycle, described below, deals with the classification of matter and is designed to provide the students with an understanding of the terms atom, molecule, element, compound, solution, and heterogeneous matter. Learning Cycle Exploration
Two or three students workine as a mouo are eiven a set of the diagrams shown in Figure 1.cach &ou
