# Justin DimmelUniversity of Maine | UM

Justin Dimmel

## About

38

Publications

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251

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## Publications

Publications (38)

Technology-mediated simulations of teaching are used increasingly to represent practice in the context of professional development interventions and assessment. Some such simulations represent students as cartoon characters. An important question in this context is whether simplified cartoon representations of students can convey similar meanings a...

In 1837, Fröbel introduced a pedagogical regimen focused on a set of simple tangible objects, beginning with a yarn ball, that children were invited to manipulate in various ways. Montessori and other educational luminaries followed this tradition of designing instructional manipulatives. Later, when digital technologies were invented for informati...

Graphical representations are ubiquitous in the learning and teaching of science, technology, engineering, and mathematics (STEM). However, these materials are often not accessible to the over 547,000 students in the United States with blindness and significant visual impairment, creating barriers to pursuing STEM educational and career pathways. F...

When students with blindness and visual impairment (BVI) are confronted with inaccessible visual graphics in the geometry classroom, additional instructional supports are often provided through verbal descriptions of images, tactile and haptic representations, and/or kinetic movement. This preliminary study examined the language used by instruction...

This paper reports on a study of learners' use of immersive spatial diagrams to make arguments about three-dimensional geometric figures. Immersive spatial diagrams allow learners to use the movement of their bodies to control their point of view, while immersed in three-dimensional digital renderings. We present analysis of two pairs of pre-servic...

In this article, we examine spatial inscriptions marked in real or rendered spaces, rather than on two-dimensional surfaces, conceptualize spatial inscriptions from an inclusive materialist perspective and consider realizations of spatial inscriptions that are possible with emerging technologies (e.g. 3D pens, immersive virtual reality). We then de...

Physical models for exploring multiplication are fixtures in elementary classrooms. The most widely used physical models of multiplication are collections of discrete things, such as Cuisenaire rods, Unifix Cubes, or Base-10 Blocks. But discrete physical models are limited in the products they can represent. By contrast, pictorial models, such as n...

In this article, we examine spatial inscriptions marked in real or rendered spaces, rather than on two-dimensional surfaces, conceptualize spatial inscriptions from an inclusive materialist perspective and consider realizations of spatial inscriptions that are possible with emerging technologies (e.g. 3D pens, immersive virtual reality). We then de...

This study analyses College of Education and Human Development an online scenario-based instrument in which secondary mathematics teachers from across the United States were presented with episodes of mathematics instruction and then asked to make a decision at a critical juncture. The theory of practical rationality suggests that the decisions of...

We investigated how US secondary mathematics teachers expect students to present geometric proofs at the board. We analyzed video records of geometry classrooms and found students to be engaged in a practice that we call proof transcription—i.e., mark-for-mark reproductions of previously completed proofs that were not reasoned reconstructions of ar...

As social media has grown, participation in virtual communities focused on the teaching and learning of mathematics has become a norm within the field of mathematics education. Little work has been done within the field to understand the evolving landscape these communities present and the boundaries that educators, both new and old, create, cross,...

We consider how dynamic diagrams can be used to model multiplication and division. This chapter begins with a review of how multiplication is conceptualized in elementary mathematics education. We consider the affordances of familiar representations of multiplication (e.g., repeated addition, the area representation) and highlight aspects of arithm...

This study investigates how spatial diagrams are used by pre-service elementary teachers to construct arguments about measures of solid figures. Dynamic spatial diagrams offer immersive three-dimensional representations of three-dimensional geometric figures, where learners can take perspectives are not accessible in two-dimensional representations...

We investigated preservice elementary teachers’ diagrammatic encounters with division by zero. Pairs of preservice teachers explored a transformable diagram where the locations of points on the x and y axes could be continuously varied. Quotients were defined in the diagram as the intersection of a line with the y-axis. For zero divisors, the quoti...

We describe how a group of secondary mathematics teachers posed and solved a real-world problem. The problem was posed by teachers on a sandbar off the coast of an island in the Bahamas, where panoramic views of water meeting sky spurred the teachers to wonder how far away they could see. We analyze how the teachers translated the natural question,...

In this theoretical research report we reflect on the challenges of becoming more fox-like in mathematics education work. Using a communities of practice motivating theoretical lens, we compare and discuss the differences in defining, creating, and accessing knowledge between virtual and scholarly communities of practice in mathematics education. W...

We report on the design and development of HandWaver, a mathematical making environment for use with immersive, room-scale virtual reality. A beta version of HandWaver was developed at the IMRE Lab at the University of Maine and released in the spring of 2017. Our goal in developing HandWaver was to harness the modes of representation and interacti...

Objectives
The state of the art for displaying and interacting with information is rapidly evolving. Technologies that allow users to interact with virtual, spatial figures have been commercially available since 2016 and are getting cheaper, smaller, and more feasible to implement in schools each month. By virtual, we refer to figures that are digi...

Pre-service elementary teachers (PSETs) have difficulties extending measurement concepts
from two-dimensional to three-dimensional figures (Tossavainen et al., 2017). This matters
because how teachers understand mathematical topics shapes how they present those topics to their students (Murphy, 2012). If the geometry activities expected of young ch...

We investigated how secondary mathematics teachers check student geometry proofs. From video records of geometry teachers checking proofs, we conjectured that teachers have different expectations for details that follow from written statements than for details that are conveyed by diagrams. To test our conjectures, we randomly assigned 44 secondary...

This is a binary built from the HandWaver project to illustrate examples of shearing with LeapMotion gesture controls.

We investigated secondary mathematics teachers' attitudes toward alternative ways of managing instruction on geometric proofs. Participants assigned to different experimental conditions viewed storyboard episodes of instruction. Some episodes showed instruction we hypothesized teachers would recognize as routine. Other episodes showed instruction t...

A room-scale virtual-reality environment was used to investigate students' conceptions of the volume of a pyramid. Participants controlled the virtual environment with a gesture-based interface that converted movements of their hands into actions on mathematical figures. Two students in graduate programs leading to certification in secondary scienc...

We report on the design and development of HandWaver, a gesture-based mathematical making environment for use with immersive, room-scale virtual reality. A beta version of HandWaver was developed at the IMRE Lab at the University of Maine and released in the spring of 2017. Our goal in developing HandWaver was to harness the modes of representation...

We examine responses from a national sample of high school mathematics teachers to a questionnaire, which had been developed to study teachers’ recognition of a system of hypothesized norms that stipulate that geometry proof problems are to be posed using a diagrammatic register. We report on the psychometric properties of the questionnaire, as wel...

Records of what takes place in mathematics classrooms are indispensable in mathematics teacher education and in research on mathematics teaching. We describe here the LessonSketch environment, an online platform for creating and analyzing representations of mathematics classrooms. We describe the authoring and analytic tools of LessonSketch with a...

In this study, we examine the use of a nondescript cartoon graphics for representing emotion in professional scenarios. The results from fifteen inservice teachers who took 33 forced-choice items identifying emotions of 20 photos of human actors and 13 nondescript cartoon graphics of students represented in classrooms will be discussed. Findings sh...

We discuss findings from a study of 226 K-12 mathematics teachers who rated the appropriateness of instructional actions in a scenario-based assessment. The teaching actions shown in the scenarios were designed to represent mathematics teachers fulfilling their obligation to the discipline of mathematics. Our analysis of the participants' follow-up...

This paper describes instruments designed to use multimedia to study at scale the instructional decisions that mathematics teachers make as well as teachers’ recognition of elements of the context of their work that might influence those decision. This methodological contribution shows how evidence of constructs like instructional norm and professi...

Geometry diagrams use the visual features of specific drawn objects to convey meaning about generic mathematical entities. We examine the semiotic structure of these visual features in two parts. One, we conduct a semiotic inquiry to conceptualize geometry diagrams as mathematical texts that comprise choices from different semiotic systems. Two, we...

This dissertation investigates how teachers expect students to represent mathematical work. The goal of the study is to identify routine ways that students communicate in mathematics classrooms and to determine whether mathematics teachers recognize these routines. The instructional setting of the study is US high school geometry. The study looks s...

We describe the development of measures of teachers' recognition of an instructional norm: that proof problems in high school geometry are presented in a diagrammatic register. A first instrument required participants to openly respond to depictions of classroom scenarios in which the norm was breached. A second instrument was a survey that require...

Using a multimedia questionnaire we explore the extent to which secondary mathematics teachers recognize a hypothesized norm of doing proofs in geometry???that the teacher is in charge of providing the 'given' and the 'prove.' We also explore whether teachers who recognize the norm make a negative appraisal of its breach and find that geometry teac...

Diagrams are key resources for students when reasoning in geometry. Over the course of the 20th century, diagrams in geometry textbooks have evolved from austere collections of strokes and letters to become diverse arrays of symbols, labels, and differently styled visual parts. Diagrams are thus multisemiotic texts that present meanings to students...