title: Multiple return separation for a full-field ranger via continuous waveform modelling

authors: Godbaz, John Peter

subjects: lidar

abstract: We present two novel Poisson noise Maximum Likelihood based methods for identifying the individual returns within mixed pixels for Amplitude Modulated Continuous Wave rangers. These methods use the convolutional relationship between signal returns and the recorded data to determine the number, range and intensity of returns within a pixel. One method relies on a continuous piecewise truncated-triangle model for the beat waveform and the other on linear interpolation between translated versions of a sampled waveform. In the single return case both methods provide an improvement in ranging precision over standard Fourier transform based methods and a decrease in overall error in almost every case. We find that it is possible to discriminate between two light sources within a pixel, but local minima and scattered light have a significant impact on ranging precision. Discrimination of two returns requires the ability to take samples at less than 90 phase shifts.

text: Multiple return separation for a full-field ranger via continuous waveform modelling We present two novel Poisson noise Maximum Likelihood based methods for identifying the individual returns within mixed pixels for Amplitude Modulated Continuous Wave rangers. These methods use the convolutional relationship between signal returns and the recorded data to determine the number, range and intensity of returns within a pixel. One method relies on a continuous piecewise truncated-triangle model for the beat waveform and the other on linear interpolation between translated versions of a sampled waveform. In the single return case both methods provide an improvement in ranging precision over standard Fourier transform based methods and a decrease in overall error in almost every case. We find that it is possible to discriminate between two light sources within a pixel, but local minima and scattered light have a significant impact on ranging precision. Discrimination of two returns requires the ability to take samples at less than 90 phase shifts.

year: 2009

title: Formative assessment in science classrooms

authors: Cowie, Bronwen

abstract: This study investigated how formative assessment was perceived, experienced and accomplished by teachers and students in ten Year 7 to 10 science classrooms. The study was undertaken within and built on the findings of the Learning in Science Project (Assessment). An interpretive methodology using interviews and participant observation was employed. The study consisted of two phases. During the first phase, the teachers and at least three students of each teacher were interviewed and three classroom observations undertaken to ascertain views of formative assessment. In phase 2, case studies were developed of the formative assessment in the different classrooms. In addition, the teachers participated in eleven teacher development days, which were audio-taped and analysed. 

While the literature provided a definition and discussion of formative assessment relatively little research had explored student perceptions and experiences of formative assessment as an aspect of their everyday classroom life. The links between formative assessment and views of learning had received very little attention. The study provides empirical evidence that formative assessment is accomplished through situated teacher and student actions and interactions that involve the exchange, interpretation and action on information about student learning. It seems teachers and students are active and intentional participants in the process of formative assessment but not necessarily for the same purposes. Student perceptions that interactions could enhance their learning and harm their relationships with others and their view of themselves led them to consider both the possible benefit and the potential harm of disclosing their ideas to others (teachers and peers). Moreover, students indicated that whether they pursued learning or performance goals and how they perceived teacher assessment purposes influenced their purposes for and willingness to participate in assessment interactions. Cognition, affect, conation and relationships with others were experienced by the students as inextricably intertwined with their learning and the formative assessment of it. Thus, the findings indicate that formative assessment contributes to the meaning of being a student, learner, knower and peer and of being a teacher in the classroom.

The findings of the study support the view that formative assessment is a sociocultural activity that may be described and is accomplished along three interdependent planes of the classroom, interpersonal and personal activity and meaning (Rogoff, 1995). On the classroom plane, formative assessment is accomplished through a process of apprenticeship and influences what it means to be a student (and a teacher). On the interpersonal plane, formative assessment is accomplished through a process of guided participation and influences what is taken and counts as school science and hence what it means to be a student (of science) in a particular classroom. It shapes how students view themselves and each other in the social milieu of the classroom. On the personal plane it shapes the language students use and how they feel about themselves as learners and knowers of school science.

text: Formative assessment in science classrooms This study investigated how formative assessment was perceived, experienced and accomplished by teachers and students in ten Year 7 to 10 science classrooms. The study was undertaken within and built on the findings of the Learning in Science Project (Assessment). An interpretive methodology using interviews and participant observation was employed. The study consisted of two phases. During the first phase, the teachers and at least three students of each teacher were interviewed and three classroom observations undertaken to ascertain views of formative assessment. In phase 2, case studies were developed of the formative assessment in the different classrooms. In addition, the teachers participated in eleven teacher development days, which were audio-taped and analysed. 

While the literature provided a definition and discussion of formative assessment relatively little research had explored student perceptions and experiences of formative assessment as an aspect of their everyday classroom life. The links between formative assessment and views of learning had received very little attention. The study provides empirical evidence that formative assessment is accomplished through situated teacher and student actions and interactions that involve the exchange, interpretation and action on information about student learning. It seems teachers and students are active and intentional participants in the process of formative assessment but not necessarily for the same purposes. Student perceptions that interactions could enhance their learning and harm their relationships with others and their view of themselves led them to consider both the possible benefit and the potential harm of disclosing their ideas to others (teachers and peers). Moreover, students indicated that whether they pursued learning or performance goals and how they perceived teacher assessment purposes influenced their purposes for and willingness to participate in assessment interactions. Cognition, affect, conation and relationships with others were experienced by the students as inextricably intertwined with their learning and the formative assessment of it. Thus, the findings indicate that formative assessment contributes to the meaning of being a student, learner, knower and peer and of being a teacher in the classroom.

The findings of the study support the view that formative assessment is a sociocultural activity that may be described and is accomplished along three interdependent planes of the classroom, interpersonal and personal activity and meaning (Rogoff, 1995). On the classroom plane, formative assessment is accomplished through a process of apprenticeship and influences what it means to be a student (and a teacher). On the interpersonal plane, formative assessment is accomplished through a process of guided participation and influences what is taken and counts as school science and hence what it means to be a student (of science) in a particular classroom. It shapes how students view themselves and each other in the social milieu of the classroom. On the personal plane it shapes the language students use and how they feel about themselves as learners and knowers of school science.

year: 2000

title: Exploring synergies between Māori pedagogy and communicative language teaching

authors: Nock, Sophie

subjects: Māori pedagogy

abstract: The primary aim of this paper is to explore potential synergies between Māori pedagogy and what is known as ‘communicative language teaching’. A brief outline of some changes and developments in approaches to language teaching and learning over the last few decades is followed by a summary of some of the main characteristics of communicative language teaching (CLT) and of different approaches to the conceptualization of Māori pedagogy. Some of the primary characteristics of communicative language teaching are then explored in the context of Māori pedagogy and it is argued that there are some important synergies between the two.

text: Exploring synergies between Māori pedagogy and communicative language teaching The primary aim of this paper is to explore potential synergies between Māori pedagogy and what is known as ‘communicative language teaching’. A brief outline of some changes and developments in approaches to language teaching and learning over the last few decades is followed by a summary of some of the main characteristics of communicative language teaching (CLT) and of different approaches to the conceptualization of Māori pedagogy. Some of the primary characteristics of communicative language teaching are then explored in the context of Māori pedagogy and it is argued that there are some important synergies between the two.

year: 2009-02