Scientific reasoning skills development in the introductory biology courses for undergraduates

concepts into the appropriate context (Hewson & Hewson, 2003). The reasoning skills found in the formal operational stage aid this process through the testing of old and 32 new concepts, as similarly described for deduction in science knowledge generation. It is therefore desirable to understand the relationship between reasoning level and conceptual change. Lawson and Weser (1990) explored this association by investigating the degree that nonscientific beliefs regarding evolution changed throughout a semester in relation to the students’ initial levels of reasoning ability. It was predicted that those students who had higher reasoning skills would be more likely to hold scientific beliefs initially and also more likely to change nonscientific beliefs. Conversely, concrete reasoners would be more likely to have and retain nonscientific beliefs. The authors did detect the predicted correlation between initial reasoning ability and initially-held scientific beliefs, with significant differences found on test items regarding evolutionary perspective and Darwin's theory. In addition, although most students tended to believe that evolution took place, those students identified as formal reasoners were more likely to hold these beliefs strongly. Lawson and Weser also found that more skilled reasoners were better adapted to change nonscientific beliefs to scientific ones. They argued that formal reasoners’ ability to consider alternative views strengthens their ability for conceptual change. However, mixed results demonstrating regression to more nonscientific beliefs on some test items, as well as the lack of many significant differences among reasoning abilities and belief changes implies that nonscientific beliefs mixed with religious convictions may be more difficult to change due to the depth of emotional investment. In contrast to investigating nonscientific beliefs which may have emotional components, Lawson, Baker, DiDonato, and Verdi (1993) used the introduction of competing theoretical concepts regarding molecular polarity, bonding, and diffusion in 33 order to determine the impact of hypothetico-deductive reasoning skills on conceptual change of scientific concepts. After being exposed to an inappropriate concept, the researchers found that reasoning skill group difference was positively and significantly related to performance on the post-test, which required students to explain diffusion through the use of the appropriate concept. These group differences were not seen on the pre-test, as may be initially expected, especially when considering the observations by Lawson and Weser (1990) that demonstrated a relationship of initial scientific beliefs to reasoning abilities. However, as the post-test required the students to consider both the inappropriate and appropriate theoretical explanations, the correlation between formal reasoning skill and performance revealed the importance of these hypothetico-deductive skills in conceptual change. In addition, the authors more closely examined those students who initially scored at a high misconception level on the pre-test. They found that, of those students, none of the concrete reasoners were able to change from holding a misconception to a correct conception, while both transitional and formal reasoners demonstrated some movement towards correct conceptions. However, with regard to addressing misconceptions through reasoning ability, one missing piece of information is the degree to which the experimenter actively pursues an increase in reasoning abilities as one of the teaching goals, as is often the case in studies where the experimenter is the teacher. If there is a significant focus on developing reasoning skill through practice, possibly on the particular misconception investigated, then the premise of the effect of initial reasoning ability on conceptual change is less valid. The replicability of these experiments is severely limited without knowledge of the degree to which reasoning skills are incorporated in the everyday classroom. Even 34 without this information, these studies, taken together, demonstrate the variety of conceptions that can be influenced by reasoning ability. Hypothetico-Deductive Reasoning Ability and Hypothesis Testing Previous work focusing on Piaget’s intellectual development stages, including those already reviewed here, has been on the four levels already described by Piaget himself. However, recent studies have found there is a possible fifth level of reasoning ability. The progression of development through the first four Piagetian levels has been associated with changes in brain function, as noted by changes in electroencephalograms (EEGs). A fifth alteration in an individual’s EEG has also been found to take place. Lawson, Drake, et al. (2000) hypothesize this change is associated with a post-formal operational stage, which they term “theoretical,” denoted by the ability to formulate hypotheses involving unseen entities such as water or gas molecules. They found that in administering quizzes that asked for hypotheses of increasing difficulty, which correlated with concrete, formal, and theoretical levels of reasoning ability, there was a decrease in the percentage of students who were able to correctly answer the questions. Although no statistical analyses were performed, the percentages of those students who succeeded on progressively difficult tasks roughly equaled the average percentages of students found at the corresponding reasoning levels. Lawson, Clark, et al. (2000) validated these findings by adjusting the previous Lawson Classroom Test of Scientific Reasoning and demonstrated there are two significantly different levels of hypothesis-testing skills. The first corresponds to the formal reasoning level and hypotheses based on visible entities and the second corresponds to the theoretical reasoning level and hypotheses generated for unseen causal 35 agents. In addition, these two levels have a significantly increasing impact on exam scores and on transfer problems designed to measure theoretical reasoning skills. Lawson, Alkhoury, et al. (2000) found a similar correlation between higher theoretical reasoning ability and a proposed new hierarchy of scientific concepts. The authors offered a designation of three levels of scientific concepts: descriptive, which involves directly observable entities; hypothetical, which involves unseen entities that are unable to be observed due to a restricted time frame (i.e. evolution); and theoretical, which involves concepts that are not directly observable. When computing multivariate analysis and pairwise comparisons, the authors found that, overall, the higher the reasoning ability, the greater the proficiency in answering questions regarding more difficult concepts. These three studies all demonstrate the presence and characteristics of a new level of intellectual development, which Lawson and colleagues have termed “theoretical.” Piaget’s basic premise of the necessity of completing one stage before advancing to the next is retained in this new schema. However, if one needs to acquire the critical skills to advance through the stages, then those individuals who have not attained these skills should not demonstrate any proficiency in the tests for levels above his or her current level. Interestingly, all three studies do demonstrate that within each reasoning stage there is proficiency variability with lower ability reasoners achieving on higher order questions. This does call into question the validity and reliability of the test of reasoning skills. However, Lawson and his colleagues postulate it is possible that lower-ability students may have enough pieces of knowledge to correctly answer a few higher-level questions or that personalogical factors, such as confidence and creativity, may be 36 interacting with reasoning ability (Lawson, Alkhoury et al., 2000; Lawson, Clark et al., 2000; Lawson, Drake et al., 2000). Overall, though, the area is still relatively new and it is possible that this intellectual level may be characterized by more than the ability to consider and test unseen entities. These studies regarding hypothesis testing and the presence of a fifth Piagetian intellectual stage are fairly new but appear promising. The validity of the newer items testing for the categorization of the theoretical level has been established through their repeated use in studies that demonstrate there is a significant difference in the abilities and achievement of students in the formal and theoretical stages. Staver and Pascarella (1984) increases this confidence by demonstrating that the method and format of the Piagetian tasks, which comprise the reasoning ability test, have no impact on the overall responses of subjects. Perhaps the greatest weakness in this area of study is the possibility of the interaction of other factors that could account for the appearance of upper-level reasoning skills in lower-level reasoners. Although this is a concern in all studies regarding Piagetian levels, more care and scrutinization need to take place when establishing a new level. Future research needs to be directed at these possible interactions, if only to discern newer individual characteristics that could have impacts on the research presented here or could further characterize Piaget’s intellectual stages. Summary The literature demonstrates that reasoning ability, when compared to cognitive style and prior knowledge, has a greater overall effect on student achievement, regardless of instructional or testing method. This statement is supported by Cavallo, Rozman, Blickenstaff, and Walker (2003/2004) who also found reasoning ability to be the best 37 predictor of achievement in a group of sophomore and junior science majors. When taking the strength of the effect of reasoning ability on achievement into account, partnering in laboratories based on reasoning ability appears to be a possi