Instructional influence of a molecular-level pictorial presentation of matter on students' conceptions and problem-solving ability

The instructional influence upon students' conceptions and problem‐solving ability of presenting pictures at the molecular level when introducing chemistry concepts and solving chemistry problems was investigated. Before instruction, the Group Assessment of Logical Thinking (GALT) was administered and its score was used as a covariate. For the treatment group, 31 pictorial materials were used during 21 hours of Korean academic high school chemistry classes. For the control group, traditional instruction was used. Six classroom observations (1 hour each in duration) for each group were made. After instruction, the Chemistry Conceptions Test, and the Chemistry Problem‐Solving Test (CPST) consisting of 10 pairs of pictorial and algorithmic problems, were administered. Korean students' success on pictorial questions from the CPST was higher than that reported in the literature for college students; however, Korean students did very poorly on algorithmic questions. The GALT score was significantly correlated with students' conceptions and problem‐solving ability. Analysis of covariance results indicated that instruction with pictorial materials at the molecular level helped students construct more scientifically correct conceptions than traditional instruction. However, use of the pictorial materials had no facilitating effect on problem‐solving ability. © 1997 John Wiley & Sons, Inc. J Res Sci Teach 34: 199–217, 1997.