Addressing the Needs of the Concrete Reasoner

Abstract

concepts like element, density and electron have attributes that are not directly observable; concrete concepts like insect, plant and rock have properties that are observable. Karplus (1977) examined nine typical concepts routinely presented to high school students: density, temperature cell, gene, environment, chemical bond, periodic system of elements, acid-base and ideal gas in terms of what reasoning patterns must be used to understand them. Temperature, cell, environment and acid-base can be presented in either concrete or abstract terms, depending upon the meaning used [i.e. temperature, either as a sensation (concrete) or as a measure of the average molecular kinetic energy in a system (abstract)]. All the others-gene, density, chemical bond, periodic system and ideal gas-can only be defined in terms of other concepts, abstractions, theories and or mathematical relationships and thus require formal reasoning ability to comprehend them. Simpson and Marek (1988) concluded that only formal reasoners were able to fully comprehend diffusion, homeostasis and food production in plants because of the multiple operational processes the student must entertain simultaneously and/or because of the abstract nature of each of the concepts. Mitchell & Lawson (1988) reported that the major source of difficulty for college students in solving genetics problems was found to lie in their lack of appropriate hypothetico-deductive reasoning skills (e.g. combinatorial, probabilistic and proportional reasoning abilities). It came as a surprise to me that many educators who responded to my article (Trifone 1987) on assessing formal reasoning ability were not aware of the percentage of their students capable of only concrete reasoning. This is not new information. Lawson and Renner (1975a), among others, have reported that nearly 65 percent of high school and 50 percent of college students (Lawson 1980) are at the concrete operational level. Recently, in my research using the Test of Logical Thinking (TOLT) to assess formal reasoning ability, more than 75 percent of freshmen and more than 60 percent of sophomores operate at the concrete operational level (Trifone 1989, unpublished data). In addition, in discussions with colleagues I have found that the reasoning abilities of the concrete reasoner have never been stressed to the secondary level educator. Many of my colleagues have for years assumed that if they simply used models and diagrams of abstract concepts, any student would be able to master most if not all of the abstract concepts typical of a high school scienceconcepts typical of a high school science