Carsten Schulte

Eye movements in code reading: relaxing the linear order

Code reading is an important skill in programming. Inspired by the linearity that people exhibit while natural language text reading, we designed local and global gaze-based measures to characterize linearity (left-to-right and top-to-bottom) in reading source code. Unlike natural language text, source code is executable and requires a specific reading approach. To validate these measures, we compared the eye movements of novice and expert programmers who were asked to read and comprehend short snippets of natural language text and Java programs. Our results show that novices read source code less linearly than natural language text. Moreover, experts read code less linearly than novices. These findings indicate that there are specific differences between reading natural language and source code, and suggest that non-linear reading skills increase with expertise. We discuss the implications for practitioners and educators.

An introduction to program comprehension for computer science educators

The area of program comprehension comprises a vast body of literature, with numerous conflicting models having been proposed. Models are typically grounded in experimental studies mostly involving experienced programmers. The question of how to relate this material to the teaching and learning of programming for novices has proven challenging for many researchers. In this critical review from a computer science educational perspective, the authors compare and contrast the way in which different models conceptualize program comprehension. This provides new insights into learning issues such as content, sequence, learning obstacles, effective learning tasks and teaching methods, as well as into the assessment of learning

Eye tracking in computing education

The methodology of eye tracking has been gradually making its way into various fields of science, assisted by the diminishing cost of the associated technology. In an international collaboration to open up the prospect of eye movement research for programming educators, we present a case study on program comprehension and preliminary analyses together with some useful tools. The main contributions of this paper are (1) an introduction to eye tracking to study programmers; (2) an approach that can help elucidate how novices learn to read and understand programs and to identify improvements to teaching and tools; (3) a consideration of data analysis methods and challenges, along with tools to address them; and (4) some larger computing education questions that can be addressed (or revisited) in the context of eye tracking.

Empirical comparison of objects-first and objects-later

In this paper, results of an empirical comparison of objects-first vs. objects-later are presented and discussed. The study was carefully designed to align the two approaches so that the comparison is focused on the main difference between the two approaches; that is the different sequence in which topics are taught: object oriented topics from the beginning or not. The study with duration of one year was carried out in a secondary school. In the end, both groups showed the same increase in learning gain, but perceived the difficulty of topics differently. We discuss study design, results and pedagogical implications.

Block Model: an educational model of program comprehension as a tool for a scholarly approach to teaching

In this paper, the Block Model, an educational model of program comprehension, is introduced. Its use for planning and analyzing lessons on algorithms is evaluated in a qualitative study with prospective computer science teachers. In addition, the background of the model, its use in computer science education research and for developing competence models is discussed.

Analysis of code reading to gain more insight in program comprehension

Code reading, although an integral part of program comprehension, is rarely reflected. In this paper, we want to argue for a research approach and direction exploiting the potential that lies in the analysis of reading processes. Based on the vast experience compiled in psychology and some studies in computing, eye tracking and think aloud were elaborated as a viable research instrument for code reading studies. We conducted a feasibility study, designed to examine the actual process of code reading as the sensory starting point of comprehension. Computational and statistical tools were developed to facilitate data capture and analysis for eye tracking experiments. Results do not just provide proof of concept but already emphasize differences between reading natural language text and source code, as well as a distinct attention allocation within different code elements like keywords and operators. In conclusion we suggest a combination of theory-driven selected stimuli material, a carefully designed procedure of eye tracking, complemented with suitable post-tests on comprehension as well as retrospective think aloud in order to obtain additional information on the linking process between perception and comprehension. As an addition to other research approaches this should most certainly help us to improve our knowledge of comprehension within an educational research framework.

Learning computer science: perceptions, actions and roles

This phenomenographic study opens the classroom door to investigate teachers’ experiences of students learning difficult computing topics. Three distinct themes are identified and analysed. Why do students succeed or fail to learn these concepts? What actions do teachers perceive will ameliorate the difficulties facing students? Who is responsible, and for what, in the learning situation? Theoretical work on threshold concepts and conceptual change deals with mechanisms and processes associated with learning difficult material [Meyer, J. and Land, R., 2005. Threshold concepts and troublesome knowledge (2): epistemological considerations and a conceptual framework for teaching and learning. Higher Education, 49 (3), 373–388; Entwistle, N., 2007. Conceptions of learning and the experience of understanding: thresholds, contextual influences, and knowledge objects. In: S. Vosniadou, A. Baltas and X. Vamvakoussi, eds. Re-framing the conceptual change approach in learning and instruction. Amsterdam, The Netherlands: Elsevier, chap. 11]. With this work as a background, we concentrate on the perceptions of teachers. Where do teachers feel that the difficulties lie when studying the troublesome knowledge in computing? Student and teacher-centric views of teaching reported in other literature are also to be seen in our results. The first two categories in the ‘what’ and ‘who’ themes are teacher-centric. Higher level categories in all themes show increasingly learner centred conceptions of the instructional role. However, the nature of the categories in the ‘why’ theme reveals a new dimension dealing with teacher beliefs specific to the nature of troublesome knowledge in computing. A number of prior studies in tertiary teaching concentrate on approaches to teaching [Trigwell, K. and Prosser, M., 2004. Development and use of the approaches to teaching inventory. Educational Psychology Review, 16 (4), 409–424], and attitudes to scholarship of teaching and learning [Ashwin, P. and Trigwell, K., 2004. Investigating educational development. In: Making sense of staff and educational development, 117–131]. Our focus on learning difficult topics extends this work, investigating teacher conceptions of causality in relation to learning difficulties. We argue that teacher conceptions of enabling factors, for learning difficult computing topics, can act to limit the nature and scope of academics’ pedagogical responses. Improved awareness of teachers beliefs regarding student learning difficulties both extends and complements existing efforts to develop a more student-centred computing pedagogy.

The use of code reading in teaching programming

Programming is an intertwined process of reading and writing. So far, computing education research has often focused on the writing part. This paper takes a further look into the role of reading source code in learning to program. In order to complement the findings from literature, we conducted interviews with programming instructors using the miracle question, on the role of code reading and comprehension. The analysis of these interviews describes this role in terms of the five categories conceptualization, occurrences, and effects of successful code reading, challenges for learners, as well as approaches to facilitate code reading. As a result, we suggest to take a further look into the different reading processes involved in programming, in order to add to the knowledge about programming instruction.

Computer science at school/CS teacher education: Koli working-group report on CS at school

In an international study, experts reflected on their national state of computer science education in school, and the associated situation and education of computer science teachers. While these situations are shaped by local circumstances, they are also shaped by changes in the discipline. The results of the study showed a number of recurrent themes and patterns such as curriculum difficulties, training and support for teachers, as well as the understanding (e.g. computer science vs. information technology) and relevance of computer science. The study also draws attention to initiatives that are being undertaken at the local and international levels to solve these problems. Finally, the study points out trends which are -- according to the experts asked -- likely to occur within the next few years.

Thinking in Objects and their Collaboration: Introducing Object-Oriented Technology

Although many professionals in education believe that an ‘objects first’ approach is the best method of introducing object-oriented technology, there is no common agreement on how to start such courses. Current study programs often begin by teaching a chosen object-oriented programing language, where students are confronted by a large amount of syntactical detail. Instead of focusing on the basics of object-oriented technology, namely objects and their collaborations, difficulties in handling the details of the programing language lead to a very scattered knowledge of object-oriented concepts. This is dangerous, as learners are left with a set of unconnected knowledge fragments. Approaches which embed different knowledge fragments in an overall knowledge view are known as “cognitive apprenticeship” approaches. The main idea of cognitive apprenticeship is continuous practice. We present a learning environment for introducing object-oriented technology in upper secondary schools based on cognitive apprenticeship. We use a visual programing language to away from the details and provide tool support to aid practice. We present the learning sequencewhich is used and show the impacts it makes on the course structure in our experiment in the chosen object-oriented programming language The Joint Task Force on Computing Curricula IEEE Computer Society.