Student conceptions of natural selection and its role in evolution

Pretests and posttests on the topic of evolution by natural selection were administered to students in a college nonmajors' biology course. Analysis of test responses revealed that most students understood evolution as a process in which species respond to environmental conditions by changing gradually over time. Student thinking differed from accepted biological theory in that (a) changes in traits were attributed to a need-driven adaptive process rather than random genetic mutation and sexual recombination, (b) no role was assigned to variation on traits within a population or differences in reproductive success, and (c) traits were seen as gradually changing in all members of a population. Although students had taken an average of 1.9 years of previous biology courses, performance on the pretest was uniformly low. There was no relationship between the amount of previous biology taken and either pretest or posttest performance. Belief in the truthfulness of evolutionary theory was also unrelated to either pretest or posttest performance. Course instruction using specially designed materials was moderately successful in improving students' understanding of the evolutionary process.     

Peer Collaboration on a Nonverbal Reasoning Task by Urban,Minority Students

An experimental study of collaborative reasoning in 86 7th-grade minority students from an urban, low-income school was conducted. The students completed items from the Test of Nonverbal Intelligence-Third Edition (TONI-3) and were asked to provide written explanations for their judgments. All students worked individually during the pretest and posttest phases of the study. During the experimental phase, some students worked independently while others worked in small, same-gender or mixed-gender groups. Significant improvements in judgments were evident during the experimental phase for all groups except the single-gender female group. The mixed-gender group reached the ceiling level of performance and outperformed both the students who worked independently and the collaborative, single-gender female group during the experimental phase. Posttest judgment scores declined and were not significantly different from pretest scores for any group. Significant improvements in written explanations for judgments were evident during the experimental phase and were maintained on the posttest by all groups. The students who collaborated had higher percentages of fully correct explanations on the posttest than students who worked alone. Collaborative experiences were beneficial for students' reasoning about unfamiliar, moderately difficult, nonverbal problems.     

Scaffolding Middle School Students’ Construction of Scientific Explanations: Comparing a cognitive versus a metacognitive evaluation approach

This study investigated the effects of scaffolds as cognitive prompts and as metacognitive evaluation on seventh-grade students' growth of content knowledge and construction of scientific explanations in five inquiry-based biology activities. Students' scores on multiple-choice pretest and posttest and worksheets for five inquiry-based activities were analyzed. The results show that the students' content knowledge in all conditions significantly increased from the pretest to posttest. Incorporating cognitive prompts with the explanation scaffolds better facilitated knowledge integration and resulted in greater learning gains of content knowledge and better quality evidence and reasoning. The metacognitive evaluation instruction improved all explanation components, especially claims and reasoning. This metacognitive approach also significantly reduced students' over- or underestimation during peer-evaluation by refining their internal standards for the quality of scientific explanations. The ability to accurately evaluate the quality of explanations was strongly associated with better performance on explanation construction. The cognitive prompts and metacognitive evaluation instruction address different aspects of the challenges faced by the students, and show different effects on the enhancement of content knowledge and the quality of scientific explanations. Future directions and suggestions are provided for improving the design of the scaffolds to facilitate the construction of scientific explanations.     

The relationship between students' learning strategies and the change in their misunderstandings during a high school chemistry course

The purposes of this study are as follows: (a) to investigate the relationship between high school students' learning approaches, prior knowledge and attitudes toward chemistry, and their performance on a misunderstandings test; and (b) to describe and analyze the differences between the responses of students with different learning approaches on the same test. Forty-nine suburban high school students enrolled in two sections of New York State Regents Chemistry classes participated in the study. The students' performance on a misunderstandings pretest and the students' learning approach both accounted for a statistically significant proportion of the variance on their performance on the misunderstandings posttest. Additionally, the results showed that the relatively meaningful learners performed significantly better than the relatively rote learners on the misunderstandings posttest.     

A window into thinking: Using student writing to understand conceptual change in science learning

This study, conducted in an inner-city middle school, followed the conceptual changes shown in 25 students' writing over a 12-week science unit. Conceptual changes for 6 target students are reported. Student understanding was assessed regarding the nature of matter and physical change by paper-and-pencil pretest and posttest. The 6 target students were interviewed about the goal concepts before and after instruction. Students' writing during lesson activities provided qualitative data about their understandings of the goal concepts across the science unit. The researcher constructed concept maps from students' written statements and compared the maps across time to assess changes in the schema of core concepts, complexity, and organization as a result of instruction. Target students' changes were studied in detail to determine patterns of conceptual change. After patterns were located in target students' maps, the remaining 19 students' maps were analyzed for similar patterns. The ideas that students identified in their writing showed changes in central concepts, complexity, and organization as the lessons progressed. When instructional events were analyzed in relation to students' demonstrated ideas, understanding of the goal conceptions appeared in students' writing more often when students had opportunities to explain their new ideas orally and in writing.     

The effect of reflective discussions following inquiry‐based laboratory activities on students' views of nature of science

This research investigated the effect of reflective discussions following inquiry‐based laboratory activities on students' views of the tentative, empirical, subjective, and social aspects of nature of science (NOS). Thirty‐eight grade six students from a Lebanese school participated in the study. The study used a pretest–posttest control‐group design and focused on collecting mainly qualitative data. During each laboratory session, students worked in groups of two. Later, experimental group students answered open‐ended questions about NOS then engaged in reflective discussions about NOS. Control group students answered open‐ended questions about the content of the laboratory activities then participated in discussions of results of these activities. Data sources included an open‐ended questionnaire used as pre‐ and posttest, answers to the open‐ended questions that experimental group students answered individually during every session, transcribed videotapes of the reflective discussions of the experimental group, and semi‐structured interviews. Results indicated that explicit and reflective discussions following inquiry‐based laboratory activities enhanced students' views of the target NOS aspects more than implicit inquiry‐based instruction. Moreover, implicit inquiry‐based instruction did not substantially enhance the students' target NOS views. This study also identified five major challenges that students faced in their attempts to change their NOS views. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 1229–1252, 2010     

Planning text structure as a way to improve students' writing from sources in the compare–contrast genre

The aim of this study was to improve 7th- and 8th-grade students' (N = 83) compare–contrast reports when writing from sources. An instructional unit was designed and implemented for this purpose. It focused on increasing students' knowledge of compare–contrast text structure and on having students memorize and use a table to plan the structure of their reports. There was a large effect size of instruction, such that students in the instruction group made far greater gains in the holistic and structural quality of their writing (from pretest to posttest) than students in the control group.     

Investigations of a complex,realistic task: Intentional,unsystematic, and exhaustive experimenters

This study examines how students' experimentation with a virtual environment contributes to their understanding of a complex, realistic inquiry problem. We designed a week‐long, technology‐enhanced inquiry unit on car collisions. The unit uses new technologies to log students' experimentation choices. Physics students (n = 148) in six diverse high schools studied the unit and responded to pretests, posttests, and embedded assessments. We scored students' experimentation using four methods: total number of trials, variability of variable choices, propensity to vary one variable at a time, and coherence between investigation goals and experimentation methods. Students made moderate, significant overall pretest to posttest gains on physics understanding. Coherence was a strong predictor of learning, controlling for pretest scores and the other experimentation measures. We identify three categories of experimenters (intentional, unsystematic, and exhaustive) and illustrate these categories with examples. The findings suggest that students must combine disciplinary knowledge of the investigation with intentional investigation of the inquiry questions in order to understand the nature of the variables. Mechanically executing well‐established experimentation procedures (such as varying one variable at a time or comprehensively exploring the experimentation space) is less likely to lead students to valuable insights about complex tasks. Our proposed categories extend and refine previous efforts to categorize experimenters by linking scientific procedures with understanding of the science discipline. © 2011 Wiley Periodicals, Inc. J Res Sci Teach 48: 745–770, 2011     

Providing Written or Oral Explanations? Differential Effects of the Modality of Explaining on Students' Conceptual Learning and Transfer

Learning-by-explaining (to fictitious others) has been shown to be an effective instructional method to support students' generative learning. In this study, we investigated differential effects of the modality of explaining (written versus oral) on students' quality of explanations and learning. Forty-eight students worked on a hypertext about combustion engines. Afterwards, they were asked to explain the learning content, either orally or in writing. Findings indicated that providing written explanations was more effective than providing oral explanations in supporting students to organize the content of the explanations. The higher levels of organization yielded higher levels of students' conceptual knowledge. In contrast, generating oral explanations, relative to written explanations, triggered students' elaborative processes to a more pronounced extent, which was more beneficial to attaining transferable knowledge. Thus, we conclude that the modality of explaining plays a critical role in learning-by-explaining inasmuch as different modes differentially support student learning.     

Cognitive foundations for science assessment design: Knowing what students know about evolution

To improve assessments of academic achievement, test developers have been urged to use an “assessment triangle” that starts with research‐based models of cognition and learning [NRC (2001) Knowing what students know: The science and design of educational assessment. Washington, DC: National Academy Press]. This approach has been successful in designing high‐quality reading and math assessments, but less progress has been made for assessments in content‐rich sciences such as biology. To rectify this situation, we applied the “assessment triangle” to design and evaluate new items for an instrument (ACORNS, Assessing Contextual Reasoning about Natural Selection) that had been proposed to assess students' use of natural selection to explain evolutionary change. Design and scoring of items was explicitly guided by a cognitive model that reflected four psychological principles: with development of expertise, (1) core concepts facilitate long‐term recall, (2) causally‐central features become weighted more strongly in explaining phenomena, (3) normative ideas co‐exist but increasingly outcompete naive ideas in reasoning, and (4) knowledge becomes more abstract and less specific to the learning situation. We conducted an evaluation study with 320 students to examine whether scores from our new ACORNS items could detect gradations of expertise, provide insight into thinking about evolutionary change, and predict teachers' assessments of student achievement. Findings were consistent with our cognitive model, and ACORNS was revealing about undergraduates' thinking about evolutionary change. Results indicated that (1) causally‐central concepts of evolution by natural selection typically co‐existed and competed with the presence of naïve ideas in all students' explanations, with naïve ideas being especially prevalent in low‐performers' explanations; (2) causally‐central concepts were elicited most frequently when students were asked to explain evolution of animals and familiar plants, with influence of superficial features being strongest for low‐performers; and (3) ACORNS scores accurately predicted students' later achievement in a college‐level evolution course. Together, findings illustrate usefulness of cognitive models in designing instruments intended to capture students' developing expertise. © 2012 Wiley Periodicals, Inc. J Res Sci Teach 49: 744–777, 2012     

Effects of conceptual assignments and conceptual change discussions on students' misconceptions and achievement regarding force and motion

The purpose of this study was to investigate the effects of conceptual assignments and conceptual change discussions on students' achievement and misconceptions about force and motion. The study was conducted with 6 physics teachers and their 18 classes, consisting of 396 high school physics students. The teachers administered the Force Misconception and Force Achievement Tests to their physics classes as a pretest. The results obtained were used to match the 18 classes statistically. Students assigned to the conceptual assignment protocol completed five conceptual assignments about force and motion. Students assigned to the discussion method participated in conceptual change discussions. At the end of the 8‐week treatment period, the same tests were administered to all students as a posttest. The data were analyzed by using multivariate analysis of covariance, followed by protected univariate F test and step‐down analysis. The statistical results showed that the conceptual change discussion was an effective means of reducing the number of misconceptions students held about force and motion. The conceptual change discussion was also found significantly effective in improving students' achievement in force and motion. © 2002 Wiley Periodicals, Inc. J Res Sci Teach 39: 1001–1015, 2002     

Qualitative graphing in an authentic inquiry context: How construction and critique help middle school students to reason about cancer

Inquiry instruction often neglects graphing. It gives students few opportunities to develop the knowledge and skills necessary to take advantage of graphs, and which are called for by current science education standards. Yet, it is not well known how to support graphing skills, particularly within middle school science inquiry contexts. Using qualitative graphs is a promising, but underexplored approach. In contrast to quantitative graphs, which can lead students to focus too narrowly on the mechanics of plotting points, qualitative graphs can encourage students to relate graphical representations to their conceptual meaning. Guided by the Knowledge Integration framework, which recognizes and guides students in integrating their diverse ideas about science, we incorporated qualitative graphing activities into a seventh grade web-based inquiry unit about cell division and cancer treatment. In Study 1, we characterized the kinds of graphs students generated in terms of their integration of graphical and scientific knowledge. We also found that students (n = 30) using the unit made significant learning gains based on their pretest to post-test scores. In Study 2, we compared students' performance in two versions of the same unit: One that had students construct, and second that had them critique qualitative graphs. Results showed that both activities had distinct benefits, and improved students' (n = 117) integrated understanding of graphs and science. Specifically, critiquing graphs helped students improve their scientific explanations within the unit, while constructing graphs led students to link key science ideas within both their in-unit and post-unit explanations. We discuss the relative affordances and constraints of critique and construction activities, and observe students' common misunderstandings of graphs. In all, this study offers a critical exploration of how to design instruction that simultaneously supports students' science and graph understanding within complex inquiry contexts.     

Learning contexts,black Cultural Ethos,and the science achievement of African American students in an urban middle school

As other countries vigorously promote rapid advancement in science, optimizing the participation of all students in the United States in science is imperative. This study focused on African American students and examined their science achievement in relation to Black Cultural Ethos (BCE), a construct rooted in psychology. Via qualitative and quantitative data obtained from a non‐random control group design, the study addressed three questions: (1) With respect to BCE, what characterizes the natural instructional contexts of two middle school science teachers? (2) What characterizes the achievement of African American students in contexts that incorporate BCE and contexts that do not? (3) What achievement patterns, if any, exist in BCE and non‐BCE instructional contexts? With regard to the natural contexts, the teachers did not incorporate BCE even when the opportunities were available to do so. Within these non‐BCE contexts, the group's mean scores on the study‐specific test that aligned with instruction decreased from pretest to posttest with approximately one‐third of the students' scores improving. When a context was altered with a moderate effect size of 0.47 to include BCE, the group's mean scores on the aforementioned test increased from pretest to posttest with two‐thirds of the students' scores improving. An illustration of the interplay between BCE and context and a consideration of the interplay as a mediating factor in research involving African American students encapsulate the significance and implications of the study's findings. © 2008 Wiley Periodicals, Inc. J Res Sci Teach 45: 665–683, 2008     

The Nature of Scientific Explanation: Examining the perceptions of the nature,quality, and “goodness” of explanation among college students,science teachers,and scientists

Issues regarding scientific explanation have been of interest to philosophers from Pre-Socratic times. The notion of scientific explanation is of interest not only to philosophers, but also to science educators as is clearly evident in the emphasis given to K-12 students' construction of explanations in current national science education reform efforts. Nonetheless, there is a dearth of research on conceptualizing explanation in science education. Using a philosophically guided framework—the Nature of Scientific Explanation (NOSE) framework—the study aims to elucidate and compare college freshmen science students', secondary science teachers', and practicing scientists' scientific explanations and their views of scientific explanations. In particular, this study aims to: (1) analyze students', teachers', and scientists' scientific explanations; (2) explore the nuances about how freshman students, science teachers, and practicing scientists construct explanations; and (3) elucidate the criteria that participants use in analyzing scientific explanations. In two separate interviews, participants first constructed explanations of everyday scientific phenomena and then provided feedback on the explanations constructed by other participants. Major findings showed that, when analyzed using NOSE framework, participant scientists did significantly “better” than teachers and students. Our analysis revealed that scientists, teachers, and students share a lot of similarities in how they construct their explanations in science. However, they differ in some key dimensions. The present study highlighted the need articulated by many researchers in science education to understand additional aspects specific to scientific explanation. The present findings provide an initial analytical framework for examining students' and science teachers' scientific explanations.     

Testing one premise of scientific inquiry in science classrooms: Examining students' scientific explanations and student learning

In this study, we analyzed the quality of students' written scientific explanations found in notebooks and explored the link between the quality of the explanations and students' learning. We propose an approach to systematically analyzing and scoring the quality of students' explanations based on three components: claim, evidence to support it, and a reasoning that justifies the link between the claim and the evidence. We collected students' science notebooks from eight science inquiry‐based middle‐school classrooms in five states. All classrooms implemented the same scientific‐inquiry based curriculum. The study focuses on one of the implemented investigations and the students' explanations that resulted from it. Nine students' notebooks were selected within each classroom. Therefore, a total of 72 students' notebooks were analyzed and scored using the proposed approach. Quality of students' explanations was linked with students' performance in different types of assessments administered as the end‐of‐unit test: multiple‐choice test, predict‐observe‐explain, performance assessment, and a short open‐ended question. Results indicated that: (a) Students' written explanations can be reliably scored with the proposed approach. (b) Constructing explanations were not widely implemented in the classrooms studied despite its significance in the context of inquiry‐based science instruction. (c) Overall, a low percentage of students (18%) provided explanations with the three expected components. The majority of the sample (40%) provided only claims without any supporting data or reasoning. And (d) the magnitude of the correlations between students' quality of explanations and their performance, were all positive but varied in magnitude according to the type of assessment. We concluded that engaging students in the construction of high quality explanations may be related to higher levels of student performance. The opportunities to construct explanations in science‐inquiry based classrooms, however, seem to be limited. © 2010 Wiley Periodicals, Inc. J Res Sci Teach 47: 583–608, 2010     

Initial Evaluation of Active Minds: A Student Organization Dedicated to Reducing the Stigma of Mental Illness

This study examined whether a new student organization, Active Minds, aimed at increasing awareness of “mental illness” and reducing stigma had an impact on students' stigma and willingness to seek psychological help. Three classes were recruited to become involved in the organization. In a pretest/posttest design, stigma and willingness to seek psychological help were compared between students who became involved in Active Minds and students who did not. Students involved in the organization showed a significant reduction in stigma if they had a history of mental illness in their families. However, willingness to seek psychological help was unaffected. The program's partial success is viewed in terms of empowerment and recovery. The peer support provided through Active Minds may help change people's negative attitudes about mental illness and encourage students to help one another in coping with their diagnoses.     

Electronic Graphic Organizers for Learning Science Vocabulary and Concepts: The Effects of Online Synchronous Discussion

This study investigated the content learning of fourth graders (N?=?92) randomly assigned to complete electronic Frayer Models on life science vocabulary by themselves or while engaging in synchronous online discussions with a partner. The use of the graphic organizers was interspersed with other science activities. After seven weeks, all students significantly improved their science content knowledge (d ≈ 0.60), but the two treatment groups did not demonstrate significantly different performance after controlling for pretest abilities. Path analysis revealed the rubric scores on students' organizers were more strongly predictive of the posttest science benchmark in the online discussion group than the independent group, suggesting that collaboratively completing Frayer Models may help bolster the relationship between reading and science.     

Skills‐Based Training and Counseling Self‐Efficacy

The authors studied the effectiveness of the skilled counselor training model (SCTM). Counseling students who completed the SCTM demonstrated greater gains in skills acquisition and counseling self‐efficacy than counseling students who did not receive the training. At pretest, the counseling students in both groups, doing self‐appraisals, rated their performance of counseling skills significantly higher than trained raters assessed the students' performance of counseling skills. At posttest, members of the control group continued to overestimate their skills levels when compared with the ratings given by the trained raters, whereas, in comparison, students who received SCTM training underestimated their performance.     

The differential effects of two self‐managed math instruction procedures: Cover,Copy, and Compare versus Copy,Cover, and Compare

This study compared the fluency and error rates produced when using the Cover, Copy, and Compare (CCC) and a modified CCC procedure (MCCC) called Copy, Cover, and Compare to complete subtraction math problems. Two second‐grade classrooms consisting of 47 total students participated in the study. The following items were administered to participants: (a) a timed pretest, (b) a timed CCC worksheet, (c) a timed MCCC worksheet, and (d) a timed posttest. Then the participants were asked which procedure they liked best. Results revealed significantly higher digits correct per minute (i.e., fluency scores) on the posttest when compared with the pretest scores. Likewise, students' fluency scores were significantly higher under the CCC condition when compared to the MCCC condition. There were no significant differences in accuracy from pretest to posttest nor between the CCC and MCCC conditions. Discussion focuses on implications for modifying instructional strategies, measuring student progress, implications for practice, and directions for future research. © 2009 Wiley Periodicals, Inc.