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We should dispense with use of the confusing term "null hypothesis" in educational research reports. To explain why the term should be dropped, the nature of, and relationship between, scientific and statistical hypothesis testing is clarified by explication of (a) the scientific reasoning used by Gregor Mendel in testing specific hypotheses derived from his general inheritance theory and (b) the statistical reasoning used in applying the chi-square statistic to his experimental data. The Mendel example is followed by application of the same pattern of scientific and statistical reasoning to educational examples. A better understanding of the related, but separate, processes of scientific and statistical hypothesis testing, including the role of scientific hypotheses (i.e., proposed explanations) and scientific predictions (i.e., expected test results), not only reveals why null statistical hypotheses and predictions need not be stated, but also reveals how we can improve the clarity of our research reports and improve the quality of the research reported by insuring that alternative scientific hypotheses and theories are in fact tested.

Children personally construct explanations of natural phenomena, some of which differ from currently accepted scientific explanations. The replacement of personal explanations with scientific explanations, as well as the development of concrete, formal, and post-formal reasoning patterns, requires self-regulation in which alternative explanations are generated and tested in a hypothetico-predictive fashion. Consequently, inquiry-based science instruction in which students explore nature; encounter puzzling observations; and, subsequently, generate and test their own explanations not only helps them acquire meaningful concepts, it also helps them develop intellectually and become scientifically literate. (Contains 2 figures, 1 table, and 1 endnote.)

The research articles published in the "Journal of Research in Science Teaching" in 1965, 1975, 1985, 1995, and in 2005 were surveyed to discover the extent to which they were theory driven. Carey and Smith's theory of the development of science epistemologies was used to frame the study. Specifically their theory posits that science epistemologies develop through three developmental levels. Persons at Level 1 view science as an inductive and descriptive enterprise. Persons at Level 2 view science in terms of hypothesis generation and test. Persons at Level 3 see science as theory driven. That is, theories are generated and their postulates are tested via planned tests with predicted consequences and theories are used to generate specific hypotheses, which in turn are tested in a similar manner. Three computer-generated surveys were conducted on each article identifying articles that contained the words theory, hypothesis, and prediction. The surveys assumed that if the reported research was guided by Level 3 epistemology, then these key terms would be likely to appear somewhere in the article. The term theory was found in only 18.0% of the 1965 articles. Percentages increased in subsequent decades, that is, to 36.5% in 1975, to 44.3% in 1985, to 58.3% in 1995, and then to 86.7% in 2005. Similar, though less dramatic, increases were also found for the terms hypothesis and prediction. Relatively few articles contained two or all three of the terms. Nevertheless, analysis of all 45 research articles appearing in 2005 revealed that most authors were generating and testing hypotheses and/or theories (presumably guided by Levels 2 or 3 epistemology) albeit in a largely implicit and sometimes inconsistent way. Suggestions for improving the quality of research and its reporting are made. (Contains 3 tables and 6 notes.)

Helping students better understand how scientists reason and argue to draw scientific conclusions has long been viewed as a critical component of scientific literacy, thus remains a central goal of science instruction. However, differences of opinion persist regarding the nature of scientific reasoning, argumentation, and discovery. Accordingly, the primary goal of this paper is to employ the inferences of abduction, retroduction, deduction, and induction to introduce a pattern of scientific reasoning, argumentation, and discovery that is postulated to be universal, thus can serve as an instructional framework to improve student reasoning and argumentative skills. The paper first analyzes three varied and presumably representative case histories in terms of the four inferences (i.e., Galileo's discovery of Jupiter's moons, Rosemary and Peter Grants' research on Darwin's finches, and Marshall Nirenberg's Nobel Prize-winning research on genetic coding). Each case history reveals a pattern of reasoning and argumentation used during explanation testing that can be summarized in an "If/then/Therefore" form. The paper then summarizes additional cases also exemplary of the form. Implications of the resulting theory are discussed in terms of improving the quality of research and classroom instruction. (Contains 1 figure, 2 tables, and 7 footnotes.)

Allchin (2006) has misinterpreted a classic case of hypothetico-deductive (HD) science in terms of his preferred "let's-gather-some-data-and-see-what-emerges" view. The misrepresentation concerns the research program of Peter and Rosemary Grant on Darwin's finches. The present essay argues that the Grants' research is HD in nature and includes a statement by Peter Grant to that effect.

Confusion persists concerning the roles played by scientific hypotheses and predictions in doing science. This confusion extends to the nature of scientific and statistical hypothesis testing. The present paper utilizes the "If/and/then/Therefore" pattern of hypothetico-deductive (HD) reasoning to explicate the nature of both scientific and statistical hypothesis testing. The central example is that of Gregor Mendel's test his theory of inheritance and the use of the chi-square statistic to determine the extent to which his predicted and experimental results match. When the processes of scientific and statistical hypothesis testing are cast in HD terms, we find that both involve hypotheses, planned tests, predictions, results and conclusions. However, the former involves causal claims, while the latter is descriptive. Importantly, connecting the two processes reveals that scientific predictions and statistical hypotheses are the same thing. Improved understanding of the similarities and differences of the two processes and their connected role in doing science can be expected to improve general scientific and mathematical literacy. It may also improve the quality of research in science and mathematics education.

Disagreements exist among textbook authors, curriculum developers, and even among science and mathematics educators/researchers regarding the meanings and roles of several key nature-of-science (NOS) and nature-of-mathematics (NOM) terms such as proof, disproof, hypotheses, predictions, theories, laws, conjectures, axioms, theorems, and postulates. To assess the extent to which these disagreements may exist among high school science and mathematics teachers, a 14-item survey of the meanings and roles of the above terms was constructed and administered to a sample of science and mathematics teachers. As expected, the science teachers performed better than the mathematics teachers on the NOS items (44.1 versus 24.7%, respectively) and the mathematics teachers performed better than the science teachers on the NOM items (59.0 versus 26.1%, respectively). Nevertheless, responses indicated considerable disagreement and/or lack of understanding among both groups of teachers concerning the meanings/roles of proof and disproof and several other key terms. Therefore it appears that these teachers are poorly equipped to help students gain understanding of these key terms. Classroom use of the "If/and/then/Therefore" pattern of argumentation, which is employed in this paper to explicate the hypothesis/conjecture testing process, might be a first step toward rectifying this situation.

Using the biology faculty of one high school (n = 9) and the mathematics faculty of another (n = 16), this study tested the hypothesis that constructivist teachers play an active role within teacher communication networks (the constructivist-teacher hypothesis). This hypothesis contrasts with the view that constructivist teachers operate alone and largely severed from communications among colleagues. Two types of representations of communication patterns among faculty members (i.e., sociographs) were created and analyzed for each faculty. One type of sociograph plotted communications concerning content/pedagogical issues while the other type plotted social/informal communications. Trained raters assessed constructivist-teaching practices using the Reformed Teaching Observation Protocol (RTOP). Positive relationships were found between constructivist-teaching practices and the frequency and significance of communications within both faculties--more so for content/pedagogical issues than for social/informal communications. Importantly, peers sought out constructivist teachers more often than they did traditional teachers, presumably seeking advice regarding teaching practice. Results support the constructivist-teacher hypothesis and indicate that constructivist teachers are not isolated from their peers. Instead, they appear to play an active role, particularly when colleagues are discussing issues related to content and pedagogy.

This study compared the relationships of self-efficacy and reasoning ability to achievement in introductory college biology. Based on the hypothesis that developing formal and postformal reasoning ability is a primary factor influencing self-efficacy, a significant positive correlation was predicted between reasoning ability and degree of self-efficacy to complete biological tasks. Further, reasoning ability was predicted to be more highly correlated with course achievement than self-efficacy. The study involved pre- and posttesting 459 introductory biology students. Both self-efficacy and reasoning ability increased during the semester. As predicted, self-efficacy and reasoning ability were positively correlated. Depending on the nature of the achievement measure, reasoning ability accounted for some 15 to 30 times more variance in achievement than self-efficacy. Also, as predicted, reasoning ability was a strong predictor of self-efficacy, but self-efficacy was not a strong predictor of reasoning ability. Self-efficacy estimates and achievement were higher for the concrete tasks than for the formal tasks and higher for the formal tasks than for the postformal tasks. In general, students tended to overestimate their abilities to carry out the concrete, formal, and postformal tasks. Results support the study's working hypothesis that intellectual development continues for some students during the college years, that a postformal level of intellectual development exists, and that reasoning ability is a primary factor influencing both self-efficacy and achievement. Student overestimation of their abilities may contribute to complacency, lack of effort, and to less than optimal achievement. Consequently, it may be advantageous early in the semester to provide students with particularly challenging tasks that "shock" them out of their complacency and perhaps increase their effort, their reasoning skills, and their achievement. (Contains 1 figure and 6 tables.)

What, if anything, do teachers need to know about how the brain works to improve teaching and learning? After all, a plumber needs to know how to stop leaks--not the molecular structure of water. And one can learn how to use a computer without knowing how a computer chip works. Likewise, teachers need to know how to help students develop intellectually and learn--not necessarily how their brains work. Nevertheless, it is important for teachers to understand that what is being discovered about how brains work supports constructivist learning theory, which in turn supports inquiry-based teaching. The goal of the present article is to explicate why this is so. The author starts with some of the basics of brain development. The author then discusses the implications of neuroscience research for science teaching and learning. (Contains 4 figures.)

A long-standing and continuing controversy exists regarding the role of induction and deduction in reasoning and in scientific inquiry. Given the inherent difficulty in reconstructing reasoning patterns based on personal and historical accounts, evidence about the nature of human reasoning in scientific inquiry has been sought from a controlled experiment designed to identify the role played by enumerative induction and deduction in cognition as well as from the relatively new field of neural modeling. Both experimental results and the neurological models imply that induction across a limited set of observations plays no role in task performance and in reasoning. Therefore, support has been obtained for Popper's hypothesis that enumerative induction does not exist as a psychological process. Instead, people appear to process information in terms of increasingly abstract cycles of hypothetico-deductive reasoning. Consequently, science instruction should provide students with opportunities to generate and test increasingly complex and abstract hypotheses and theories in a hypothetico-deductive manner. In this way students can be expected to become increasingly conscious of their underlying hypothetico-deductive thought processes, increasingly skilled in their application, and hence increasingly scientifically literate.

Working from the 1970s to the early 1990s, Walter Alvarez and his research team sought the cause of the mass extinction that claimed the dinosaurs 65 million years ago. The present paper discusses that research in terms of eight puzzling observations, eight episodes of hypothetico-predictive reasoning, enumerative induction, and Jung's interrogative theory of scientific discovery. The Alvarez case history paints scientific discovery as a process in which causal questions are raised and answered through the creative use of analogical reasoning followed by an equally creative process of hypothesis testing in which predicted and observed results are compared. According to this account, puzzling observations, causal hypotheses, and imagined tests drive investigations and the search for evidence. Two implications follow. The first concerns the education of new scientists and science education researchers and the need to more clearly differentiate hypotheses from predictions in the research process. The second concerns standard science classroom instruction that should more frequently engage students in open inquiries that raise causal questions and encourage the generation of alternative causal hypotheses, which can then be explicitly tested in a hypothetico-predictive fashion.

The Arizona Collaborative for Excellence in the Preparation of Teachers (ACEPT) Program is one of several reform efforts supported by the National Science Foundation. The primary ACEPT reform mechanism has been month-long summer workshops in which university and community college science and mathematics faculty learn about instructional reforms and then attempt to apply them in their courses. Previous ACEPT evaluation efforts suggest that, when implemented, the reforms boost undergraduate student achievement. The initial purpose of the present study was to discover whether enrollment of preservice teachers in one or more of these reformed undergraduate courses is linked to the way they teach after they graduate and become in-service teachers. Assuming that a link is found, a second purpose was to discover whether the presumed positive effect is in turn linked to their students' achievement. In short, the answer appears to be yes, at least among the biology teachers and students surveyed. Compared with controls, the biology teachers who had enrolled in one or more ACEPT reformed course during their teacher preparation program demonstrated significantly higher scores on the measure of reformed instruction and their students demonstrated significantly higher achievement in terms of scientific reasoning, nature of science, and biology concepts. These results support the hypothesis that teachers teach as they have been taught. Furthermore, it appears that instructional reform in teacher preparation programs including both methods and major's courses can improve secondary school student achievement. (Contains 1 note, 2 tables, and 4 figures.)

This paper explicates a pattern of scientific argumentation in which scientists respond to causal questions with the generation and test of alternative hypotheses through cycles of hypothetico-predictive argumentation. Hypothetico-predictive arguments are employed to test causal claims that exist on at least two levels (designated stage 4 in which the causal claims are perceptible, and stage 5 in which the causal claims are imperceptible). Origins of the ability to construct and comprehend hypothetico-predictive arguments at the highest level can be traced to pre-verbal reasoning of the sensory-motor child and the gradual internalization of verbally mediated arguments involving nominal, categorical, causal and, finally, theoretical propositions. Presumably, the ability to construct and comprehend hypothetico-predictive arguments (an aspect of procedural knowledge) is necessary for the construction of conceptual knowledge (an aspect of declarative knowledge) because such arguments are used during concept construction and conceptual change. Science instruction that focuses on the generation and debate of hypothetico-predictive arguments should improve students' conceptual understanding and their argumentative/reasoning skills. (Contains 4 figures and 1 table.)

According to Piaget's theory, maturation of the nervous system is sufficient for the development of formal thought. If this were the case, the job of the educational system would be small indeed. Rather, maturation determines only the totality of possibilities and impossibilities at a given stage. This study investigates whether instructional procedures can be designed and employed to successfully affect the transition from concrete to formal cognitive functioning in fifth and seventh-grade students with regard to one aspect of formal thought. Thirty-two fifth grade students and 32 seventh-grade students enrolled in an elementary school and a junior high school in Lafayette, California, served as subjects. Results suggest that instructional procedures can affect the transition from concrete to formal cognitive functioning in fifth- and seventh-grade students. Some implications for teaching are also discussed. (Contains 4 tables and 1 figure.)

Criticizes Allchin's article about Lawson's analysis of Galileo's discovery of Jupiter's moons. Suggests that a careful analysis of the way humans spontaneously process information and reason supports a general hypothetico-deductive theory of human information processing, reasoning, and scientific discovery. (SOE)

Assessed Kolb learning styles and neo-Piagetian development levels of students who then completed a lecture/lab course with either inquiry or expository instructional methods. The predicted interaction between Kolb's thinking/feeling learning dimension and instructional method was not found, while thinking/feeling dimension and developmental level both correlated positively with achievement under both instructional methods. Thinking/feeling dimension and developmental level also correlated. (EV)

Given that hypothetico-deductive reasoning has played a role in other important scientific discoveries, asks the question whether it plays a role in all important scientific discoveries. Explores and rejects as viable alternatives possible alternative scientific methods such as Baconian induction and combinatorial analysis. Discusses the educational implications of this hypothetico-deductive view of science. (Author/MM)

Investigates the responses of a sample of preservice biology teachers enrolled in a teaching methods course to a casual question about why water rose in a jar inverted over a burning candle placed in a pan of water by formulating and testing six hypotheses. (Contains 43 references.) (Author/YDS)

Introduces the learning cycle method in the context of biology instruction. Includes a theoretical rationale for its use as well as a brief review of key studies that have found it effective. (Author/MM)

Investigates the role of complex instructional analogies on concept acquisition in an introductory college genetics course. An experimental treatment included complex instructional analogies. A control group received expository instruction alone. Finds significant differences in student achievement in favor of the experimental group. (Author/MM)

Tests the hypothesis that two general developmentally-based levels of hypothesis-testing skills exist. Finds a positive relationship between level of hypothesis-testing skill and performance on a transfer problem involving the test of a hypothesis based on unobservable entities. Also finds a positive relationship between level of hypothesis-testing skill and course performance. (Contains 55 references.) (Author/WRM)

Tests the hypothesis that an early adolescent brain growth plateau and spurt exists, and that this plateau and spurt influence students' ability to reason scientifically and to learn theoretical science concepts. Finds that measures of students' (n=210) prefrontal lobe activity correlated highly with scientific reasoning ability, and that these factors predicted concept gains and posttest performance. (Contains 78 references.) (Author/WRM)

Tests the hypothesis that a fifth stage of intellectual development characterized by the ability to test alternative explanations involving unseen theoretical entities exists. This hypothesis is tested in the context of a nonmajor college-level biology course in which the assumption is made that some students have acquired Stage 5 reasoning skills. (SAH)

Presents examples using hypothetico-deductive thinking to better teach and understand biology, geology, physics, and chemistry. The examples show that hypothetico-deductive thinking is not new to science as it can be found in research from the Middle Ages. (SAH)

Offers a resolution to the debate between constructivists and realists regarding the epistemological status of human knowledge. Presents evidence in the form of three case studies and one experimental study. Concludes that knowledge acquisition involves a pattern idea generation and test that, when cast in the form of a verbal argument, follows an if/then/therefore pattern. (Author/SAH)

Tests the hypothesis that maturing prefrontal lobes play a role in the development of proportional reasoning skill because the prefrontal lobes are involved in the inhibition of task-irrelevant information and the representation of task-irrelevant information. Assigns students randomly to manipulative or verbal tutoring groups and tests both groups on proportional reasoning. (Contains 50 references.) (Author/YDS)

Extends prior theory and research by postulating the existence of an intermediate class of concepts called 'hypothetical'. Investigates the hypothesis that three kinds of scientific concepts exist by constructing and administering a test on concepts introduced in a college biology course. Supports the hypothesis that intellectual development continues beyond the formal stage during college years. (Contains 60 references.) (Author/YDS)