Publications

In this paper, we demonstrate the fruitfulness of a theoretical framework called Commognition, developed in the context of mathematics education research, for conceptualizing and analyzing a professional development (PD) process on measurement uncertainty for secondary physics teachers. Evaluating measurement uncertainty is an important learning goal in the physics lab and is key to determining the validity of an experiment. While research has mapped difficulties students face and teaching strategies to support them, teacher PD still requires attention, both in capturing teachers' existing perceptions and in designing PD activities that address these perceptions and support teachers in adopting a more scientifically aligned discourse on measurement uncertainty. Commognition perceives learning as becoming a participant in the discourse of a specific professional community. A discourse consists of keywords, visual mediators, narratives, and routines - and metarules that govern their use. The appropriation of a new discourse involves reconciling conflicts between the metarules of learners' existing discourse and the new discourse (i.e., commognitive conflicts). We adopted the commognitive framework in all phases of our PD design. First, we mapped the canonical discourse we intended our teachers to adopt versus the prevailing discourse of physics teachers in our national context. Following this mapping, we designed PD tasks intended to lead participants to acknowledge the limitations of their existing discourse on measurement uncertainty as a precursor to internalizing the canonical discourse. Finally, the commognitive framework served as an analytical lens to detect commognitive conflicts involved in collaborative sensemaking among the teachers and between them and the PD facilitators. We demonstrate this type of analysis in a case study, in which learners who hold different discursive metarules encounter implicit commognitive conflicts and discuss implications and untapped opportunities for physics teachers' PD process on measurement uncertainty.

Grading can shape students' learning and encourage use of effective problem solving practices. Teaching assistants (TAs) are often responsible for grading student solutions and providing feedback, thus, their perceptions of grading may impact grading practices in the physics classroom. Understanding TAs' perceptions of grading is instrumental for curriculum developers as well as professional development leaders interested in improving grading practices. In order to identify TAs' perceptions of grading, we used a data collection tool designed to elicit TAs' considerations when making grading decisions as well as elicit possible conflicts between their stated goals and actual grading practices. The tool was designed to explicate TAs' attitudes towards research-based grading practices that promote effective problem solving approaches. TAs were first asked to state their goals for grading in general. Then, TAs graded student solutions in a simulated setting while explicating and discussing their underlying considerations. The data collection tool was administered at the beginning of TAs' first postgraduate teaching appointment and again after one semester of teaching experience. We found that almost all of the TAs stated that the purpose of grading was formative, i.e. grading should encourage students to learn from their mistakes as well as inform the instructor of common student difficulties. However, when making grading decisions in a simulated setting, the majority of TAs' grading considerations focused on correctness and they did not assign grades in a way that encourages use of effective problem solving approaches. TAs' perceptions of grading did not change significantly during one semester of teaching experience.

We present a study of a first step in a large-scale intervention designed to shift lab instruction away from tightly prescribed lab norms. The intervention was implemented in a national network of Professional Learning Communities of high school physics teachers (N=250) operating in a high-stakes exam setting with limited resources, and catering to diverse groups of students. A pre-intervention survey examined learning goals that the teachers value as well as practices taking place in their lab lessons. The findings revealed a gap between the importance that teachers attributed to scientific practices such as experimental design and the manifestation of these goals in the national lab exam. In addition, the survey revealed disparities between the scientific practices that teachers believe that their students engage in during the instructional lab and the practices they identify in physicists' work in research labs. The intervention consisted of a series of Restricted Inquiry Labs (RILs) designed to address the teachers' interest in change as well as the constraints imposed by the setting in which they work by modest restructuring of traditional labs such as encouraging students to reflect on the considerations underlying the experimental design. The intervention proved successful in that half of the teachers reported that they introduced the RILs. They described students' engagement when granted more autonomy in designing an experiment, as well as students' difficulties in coping with a more open-ended task. Implementation of the RILs also created challenges in class management. Despite these challenges, most teachers reported that they intended to keep using RILs. Teachers asked to re-design assessment policies to emphasize scientific inquiry. The RILs proved to be a feasible way to introduce change towards inquiry-oriented labs via professional development programs, while pointing out aspects that need to be addressed to respond to teachers' concerns.

Posing the same physics problem scenario in different ways can emphasize learning goals for students, such as developing expert-like problem-solving approaches. In this investigation, we examined graduate teaching assistants' (TAs') views about a context-rich introductory physics problem within a semester-long TA professional development course. The TAs were asked to list the pros and cons of a context-rich problem, rank the problem in terms of its instructional benefit and the level of challenge it might produce for their students, and describe when and how often they would use it in their own classes if they had complete control of teaching the class. We find that TAs did not find the context-rich problem to be instructionally beneficial and were unlikely to use it in their own courses. Many TAs expressed their concerns as being due to the problem seeming to be unclear or excessively challenging and time-consuming for their students. These findings suggest that there is a discrepancy between the TAs' perception of a context-rich problem and the benefits of problems posed in this manner according to the physics education research literature.

Physics graduate teaching assistants (TAs) are often responsible for grading. Physics education research suggests that grading practices that place the burden of proof for explicating the problem solving process on students can help them develop problem solving skills and learn physics. However, TAs may not have developed effective grading practices and may grade student solutions in introductory and advanced courses differently. In the context of a TA professional development course, we asked TAs to grade student solutions to introductory physics and quantum mechanics problems and explain why their grading approaches were different or similar in the two contexts. TAs expected and rewarded reasoning more frequently in the QM context. Our findings suggest that these differences may at least partly be due to the TAs not realizing that grading can serve as a formative assessment tool and also not thinking about the difficulty of an introductory physics problem from an introductory physics student's perspective.

Teaching assistants (TAs) are often responsible for grading student solutions. Since grading communicates instructors' expectations, TAs' grading decisions play a crucial role in forming students' approaches to problem solving (PS) in physics. We investigated the change in grading practices and considerations of 18 first-year graduate students participating in a TA professional development (PD) course. The TAs were asked to state their beliefs about the purpose of grading, to grade a set of specially designed student solutions, and to explain their grading decisions. We found that after one semester of teaching experience and participation in PD, TAs did not significantly change their goals for grading (i.e., a learning opportunity for both the student and the instructor) or their grading practice. In addition, TAs' grading practice frequently did not align with their goals. However, some TAs' perceptions of the level of explication required in a student solution did change. Our findings suggest that in order for PD to help TAs better coordinate their goals with appropriate grading practices, PD should focus on TAs' perception of sufficient reasoning in student solutions.

When a system exchanges energy with a constant-temperature environment, the entropy of the surroundings changes. A lattice model of a fluid thermal reservoir can provide a visualization of the microscopic changes that occur in the surroundings upon energy transfer from the system. This model can be used to clarify the consistency of phenomena such as crystallization or similar phase transitions with the second law of thermodynamics; in those phenomena, students intuitively grasp that the system entropy decreases, but may not have a clear picture of how it is compensated by an increase in the reservoir entropy. The model may be used in the classroom to visually demonstrate how processes in which the entropy of the system decreases can occur spontaneously; specifically, it shows how the reservoir temperature affects the magnitude of the entropy change that occurs upon energy transfer from the system.

A troubleshooting activity was carried out by an e-tutor in two steps. First, students diagnosed a mistaken statement and then compared their diagnosis to a teacher's diagnosis provided by the e-tutor. The mistaken statement involved a widespread tendency to over-generalize Ohm's law. We studied the discourse between pairs of students working with the e-tutor to examine whether and how the activity attained its objective of engaging students in knowledge integration processes; namely to elicit students' ideas, add scientifically acceptable or non-acceptable ideas and support them in developing criteria to sort out their ideas. We focus here on two case studies involving a pair of students with high prior knowledge and a pair with poor prior knowledge. The micro-analysis of these two pairs shows how the activity triggered students to explicate multiple alternative interpretations of the principles and concepts involved and attempts to align conflicting conceptions. We discuss how successive emendations gradually culminated in the elaboration of the students' understanding of these concepts.

When classroom teachers introduce curricular innovations that conflict with their former deeply rooted practices, the teachers themselves experience a process of change. One professional development framework intended to support this change is the customization workshop, in which teachers cooperatively customize innovations to their own classroom contexts, reflect on the strengths and weaknesses of classroom implementation, and refine their innovations. Two goals sometimes conflict in such workshops: developing teachers' skills as reflective practitioners (process) and maintaining crucial characteristics of the original innovations (product). This paper explores how to meet both challenges using the insights from a perspective that provides a striking parallel: developing expertlike problem-solving skills (process) as well as conceptual understanding (product) in the physics classroom. We apply this perspective by (a) characterizing an expertlike approach to pedagogical problem solving in the context of customization workshops, (b) determining the nature of pedagogical problems best suited for developing such an expertlike approach, (c) suggesting how to design customization workshops that support teachers to develop an expertlike approach to pedagogical problem solving. In particular, we hypothesize that applying cognitive apprenticeship in customization workshops in a manner similar to its application in the teaching of expertlike problem solving in the physics classroom should effectively help teachers approach the pedagogical problem of customization in an expertlike manner. We support our hypothesis with an empirical study of three year-long cooperative customization workshops for physics teachers that differed in terms of mentoring approach. We examined the questions (a) under which mentoring approaches did teachers perform an expertlike pedagogical problem-solving process and (b) which practices and perceptions emerged through execution of this process?

"Self-diagnosis tasks" are aimed at fostering diagnostic behavior by explicitly requiring students to present diagnosis as part of the activity of reviewing their problem solutions. Recitation groups in an introductory physics class of about 200 college students were distributed into a control group and three intervention groups in which different levels of guidance were provided for performing self-diagnosis activities. We investigated how well students self-diagnose their solutions in the different interventions and examined the effect of students' self-diagnosis on subsequent problem solving in the different intervention groups. We found that in the context of an atypical quiz, while external support altered the self-diagnosis performance, the self-diagnosis score was not correlated with subsequent problem-solving performance on a transfer problem. We discuss possible explanations for our findings.

This paper focuses on an online activity dealing with a mistaken answer to a problem that is attributed to a student named "Danny'. Students are first required to diagnose the mistake: 1) identify the mistaken part in Danny's answer; 2) explain the nature of the mistake; 3) correct. Later on, the students receive exemplary diagnosis and are asked to compare it to their own diagnosis. The mistaken statements represent common mistaken interpretations to scientific concepts and principles related to the topic of DC circuits that are known from the research literature. In order to examine if and how the activity attains its goal to engage students in a process of clarifying and repairing the mistaken ideas underlying the mistaken answer, we performed meta- analysis of the discourse that takes place between two high school students working on the activity. The analysis focused on two aspects: 1) The physics concepts and principles required to diagnose the mistaken statement. 2) "Acknowledging conflict" statements. We found that students' conceptual change occurred gradually and involved several withdrawals along the way. In this paper we will describe how the interaction with the on-line activity triggered this process. מאמר זה מתמקד בפעילות מתוקשבת במרכזה עומדת תשובה מוטעית לבעיה, המוצגת בפיו של התלמיד "דני". התלמידים מתבקשים בשלב ראשון לאבחן את הטעות: 1 (לזהות את החלק המוטעה בתשובה 2 (להסביר את מהות הטעות. 3 (לתקנה. בשלב השני התלמידים מתבקשים להשוות את אבחונם לאבחון "מומחה" לתשובה המוטעית. התשובה המוטעית מייצגת תפיסה מוטעית נפוצה של תלמידים בנושא מעגלי זרם ישר. מטרת המערכת להניע את התלמידים ללבן את הרעיונות הפיסיקליים המוטעים העומדים בבסיס התשובה המוטעית. במטרה לבחון האם וכיצד מעודדת המערכת תהליכי ליבון מושגי, ביצענו מטה- אנליזה של שיח בין שני תלמידי פיזיקה בתיכון המשוחחים ביניהם במהלך העבודה מול המערכת. הניתוח התמקד בייצוג שני היבטים: א) רעיונות פיסיקאליים המובעים ע"י התלמיד, נכונים ומוטעים ב) "רגעי ערעור" המובילים לליבון מושגי. מצאנו כי השינוי התפיסתי בפעילות התרחש באופן הדרגתי לאורך הפעילות וכלל לא מעט נסיגות. ליבון המושגים בפעילות התרחש בשני מהלכים. המהלך הראשון, בשלב האבחון, הונע על ידי המתח בין המידע שנמסר מהמערכת, שתשובתו של דני מוטעית, לבין הזדהותם של התלמידים עם תשובתו של דני ועורר אצל התלמידים קונפליקטים פנים ובין אישיים. המהלך השני, בשלב ההשוואה לאבחון ה"מומחה, הונע ע"י מידע שהמערכת מוסיפה לתלמידים: אבחון נכון ותשובה נכונה לבעיה. מידע זה, המתווסף לאחר הצפת ההתלבטויות בשלב הראשון, הביא לשינוי מושגי ביחס למרבית הרעיונות הפיסיקליים הנידונים בפעילות.

בשלוש השנים האחרונות מתקיימת תכנית ייחודית בשם "חומר רך ומבולגן" המיועדת לתלמידים הלומדים במגמת כימיה או פיזיקה ברמת 5 יחידות לימוד. התכנית, בהיקף 2 יח"ל, היא תוצר של שתוף פעולה בין המחלקה להוראת המדעים והמחלקה לחומרים ופני שטח במכון ויצמן, ובית הספר למדע עכשווי במכון דוידסון לחינוך מדעי. במסגרת התכנית התלמידים מכירים מודלים מתחום התרמודינמיקה הסטטיסטית המסבירים תופעות מורכבות, החל מהפרדת פאזות בתערובות בינאריות, המשך להתארגנות עצמית של מולקולות סבון, וכלה במודלים לתמיסות של פולימרים. להלן נספר מעט על חומרים רכים, נציג את המסגרת התאורטית המשמשת להבנת הפרדת פאזות בתערובות בינאריות והתארגנות עצמית של חומרים פעילי שטח כמו סבון, ונציג ניסוי המאפשר לאשר את המודל התיאורטי.

What happens when students are required to engage in a self-diagnosis task; in other words get time and credit for identifying mistakes they made assisted by a sample solution? We examine this question using data collected on 180 high school students in the Arab sector in Israel. Students were able to find significant differences between their solutions and the sample solution. Yet many did not provide self-explanations indicating that they acknowledged a conflict between their mental models and the scientific model. Further, students also addressed non-significant differences. They apparently referred to the sample solution as an ultimate template and identified external deviations from it as flaws or weaknesses. Students reflected on their personal solution process, and the materials used in the task. The findings suggest allocating time for scaffolding 'self-diagnosis'.

Expert problem solvers are characterized by continuous evaluation of their progress towards a solution. One characteristic of expertise is self-diagnosis directed towards elaboration of the solvers' conceptual understanding, knowledge organization or strategic approach. "Self-diagnosis tasks" aim at fostering diagnostic behavior by explicitly requiring students to present diagnosis as part of the activity of reviewing their problem solutions. We have been investigating how introductory physics students perform in such tasks. Developing a robust rubric is essential for objective evaluation of students' self-diagnosis skills. We discuss the development of a grading rubric that takes into account introductory physics students' content knowledge as well as analysis, planning and presentation skills. Using this rubric, we have found the inter-rater reliability to be better than 80%. The rubric can easily be adapted to other problems, as will be discussed in a companion paper.

To identify and describe the basis upon which instructors make curricular and pedagogical decisions, we have developed an artifact-based interview and an analysis technique based on multilayered concept maps. The policy capturing technique used in the interview asks instructors to make judgments about concrete instructional arfifacts similar to those they likely encounter in their teaching environment. The analysis procedure alternatively employs both an a priori systems view analysis and an emergent categorization to construct a multilayered concept map, which is a hierarchically arranged set of concept maps where child maps include more details than parent maps. Although our goal was to develop a model of physics faculty beliefs about the teaching and learning of problem solving in the context of an introductory calculus-based physics course, the techniques described here are applicable to a variety of situations in which instructors make decisions that influence teaching and learning.

This paper presents preliminary hypotheses about a common core of faculty beliefs about how their students learn to solve problems in their introductory courses. Using a process of structured interviews and a concept map based analysis, we find that faculty appear to believe that students learn problem solving primarily through a process of reflective introspection (educators call this process metacognition) while they practice solving problems and getting assistance from example problem solutions.