An Experiment on Using Roles of Variables in Teaching Introductory Programming

Roles of variables is a new concept that captures tacit expert knowledge in a form that can be taught in introductory programming courses. A role describes some stereotypic use of variables, and only ten roles are needed to cover 99% of all variables in novice-level programs.

This paper presents the results of an experiment where roles were introduced to novices learning Pascal programming. Students were divided into three groups that were instructed differently: in the traditional way with no treatment of roles; using roles throughout the course; and using a role-based program animator in addition to using roles in teaching.

The results show that students are not only able to understand the role concept and to apply it in new situations but—more importantly—that roles provide students a new conceptual framework that enables them to mentally process program information in a way demonstrating good programming skills. Moreover, the use of the animator seems to foster the adoption of role knowledge.     

What's wrong? Understanding beginners' problems with Prolog

This paper reviews psychological research on programming and applies it to the problems of learning and teaching Prolog. We present a psychological model that explains how a certain class of errors in programs comes about. The model fits quite well with the results of a small sample of students and problems. The problems that underlie these and other errors seem to be (a) the complexity of the Prolog primitives (unification and backtracking) and (b) the misfit between students' naive solutions to a problem and the constructs that are available in Prolog (e.g. iterative solutions do not map easily to recursive programs). This suggests that learning Prolog could be helped by (1) coherent and detailed instruction about how Prolog works, (2) emphasis on finding recursive solutions that do not rely on primitives such as assignment and (3) instruction in programming techniques that allow students to implement procedural solutions.     

含竖直裂纹弹性材料与梯度材料粘接的接触问题

从功能梯度材料的弹性理论出发,首先推导出梯度材料在不同边界条件下的状态方程,进而使用Fourier变换技术将含裂纹弹性材料与梯度材料粘接的接触问题转化为边值问题,建立起该数学模型。构造带技巧性的积分变换方法将混合边值问题化为奇异积分方程,并利用Gauss—Chebyshev积分公式将奇异积分方程离散为计算机可实现的代数方程组,编制计算机程序并上机调试,得出数值模拟结果。     

指针错误辨析

指针的概念在C语言程序设计中较其它概念难以理解和掌握,在学习和使用中容易出错,因此在学习和使用中要多仔细思考,多比较,多上机调试,弄清细节,并从中积累经验,才能找出程序中的隐蔽的错误,使程序经得起考验,从而达到正确掌握和使用指针的目的。     

Programming Pluralism: Using Learning Analytics to Detect Patterns in the Learning of Computer Programming

New high-frequency, automated data collection and analysis algorithms could offer new insights into complex learning processes, especially for tasks in which students have opportunities to generate unique open-ended artifacts such as computer programs. These approaches should be particularly useful because the need for scalable project-based and student-centered learning is growing considerably. In this article, we present studies focused on how students learn computer programming, based on data drawn from 154,000 code snapshots of computer programs under development by approximately 370 students enrolled in an introductory undergraduate programming course. We use methods from machine learning to discover patterns in the data and try to predict final exam grades. We begin with a set of exploratory experiments that use fully automated techniques to investigate how much students change their programming behavior throughout all assignments in the course. The results show that students’ change in programming patterns is only weakly predictive of course performance. We subsequently hone in on 1 single assignment, trying to map students’ learning process and trajectories and automatically identify productive and unproductive (sink) states within these trajectories. Results show that our process-based metric has better predictive power for final exams than the midterm grades. We conclude with recommendations about the use of such methods for assessment, real-time feedback, and course improvement.     

Experiences,activities, and personal characteristics as predictors of engagement in STEM-focused summer programs

Out-of-school-time programs for youth that are focused on STEM content are often seen as affording opportunities to increase youth engagement, interest, and knowledge in STEM domains, yet we know relatively little about how youth actually experience such programs. In this article, we explore how experiences and activities employed in the delivery of summer STEM programs are associated with youth engagement during programming, and whether youth characteristics moderate these relationships. Data were collected from 203 youth (ages 10–16) in nine summer programs using multiple methods including video, experience sampling, and surveys. Through the use of cross-classified, multi-level models, we found that youth reported higher engagement in program activities they perceived to be more challenging and relevant, and in activities, they perceived to have more affordances for learning or developing skills. Gender moderated these relationships such that the positive relationships observed among males were muted or nonexistent for girls. We further identify that program activities are differently associated with fostering challenge, relevance, and learning. Findings have implications for out-of-school STEM programming for youth.     

开放式数据库互连(ODBC)技术的探讨

在当今的IT界，数据库编程越来越重要，但是当让应用程序用不同的接口分别访问这些数据源，则应用程序的开发将不胜其烦，Microsoft的ODBC技术将解决这一难题。利用ODBC，我们可通过统一界面和好多各不相同的数据库打交道，本文重点对ODBC的基本思想和ODBC API应用结构进行了探讨，并通过一个实例说明ODBC API函数的使用过程。     

Digital Computer Calculation of the Operation of Nonlinear Devices with Energy Storage Elements

This paper presents results on digital computer calculation of the operation of some tube and transistor circuits which combine nonlinear operation with energy storage elements. The Class C amplifier, the frequency multiplier and the blocking oscillator are all circuits of this type. This approach allows many of the conventional restrictions on analysis procedures to be removed. For instance, in the case of the Class C amplifier, it is not necessary to assume that the plate and grid voltages are sinusoidal and the circuit at steady state. Additional features of computer use are the automatic calculation of efficiencies, plotting of waveforms and calculation of harmonic content; the facility of studying the effects of transients and modulation; the possibility of allowing the circuit parameters to take on any values or vary with time or with the voltages and currents; and the possibility of allowing the circuit associated with the device to be more complicated than usually allowed by other methods. Limitations to this approach lie in the cost of programming the problem, and the cost of running the program on an available computer. Questions of numerical accuracy sometimes arise, but can usually be handled with additional programming or running time. If a translator is available which can accept programs in the form of algebraic equations, the programming cost is often negligible. However, running time costs may be appreciable, particularly in the case of a complicated circuit with many storage elements.     

宏指令在数控铣削手工编程中的综合应用

宏指令可以简化数控编程,并扩展数控系统的插补能力。本文以数控技能大赛的实操题为例,详细分析了如何在数控铣削手工编程中合理运用宏指令。     

Tools to make C programs safe： a deeper study

The C programming language is expressive and flexible, but not safe; as its expressive power and flexibility are obtained through unsafe language features, and improper use of these features can lead to program bugs whose causes are hard to identify. Since C is widely used, and it is impractical to rewrite all existing C programs in safe languages, so ways must be found to make C programs safe. This paper deals with the unsafe features of C and presents a survey on existing solutions to m…     

使用VBA处理地质数据的方法及步骤——以Excel二次编程为例

VBA是一类适用面广、功能强大的编程语言,能通过控制应用程序运行而实现办公自动化,因而在处理地质数据和绘制图形等方面拥有很大的开发前景。笔者提出一种编程步骤及编程技巧,非常适于没有编程经验的地质工作者使用。操作者不仅可以自行发开和发布工作程序,也可以使用和修改他人的程序,从而使地质工作的自动化水平得到整体的提升。     

改善农业电视节目提高农村留守妇女科教水平

农业类电视节目的独特优势能够满足农村留守妇女因角色转换而产生的对科技知识的新需求,但它有很多不完善之处。传播者要了解农村留守妇女的需求,创办她们喜欢的节目;健全电视网络,提高农业节目的到达率;提升节目主持人及制播人员的综合素质,这样才能达到预期的效果。     

电大试点教学点建设若干问题刍议

试点教学点是试点教学的具体实施单位。加强试点教学点的建设，是增强电大系统整体办学功能和优势的关键所在，直接关系到能否保证试点工作的顺利实施和人才培养模式改革的深入进行，关系到能否进一步促进电大事业健康稳定可持续发展。本文就如何加强试点教学点建设的几个方面做些探讨。     

A Survey of Automated Assessment Approaches for Programming Assignments

Practical programming is one of the basic skills pursued in computer science education. On programming courses, the coursework consists of programming assignments that need to be assessed from different points of view. Since the submitted assignments are executable programs with a formal structure, some features can be assessed automatically. The basic requirement for automated assessment is the numerical measurability of assessment targets, but semiautomatic approaches can overcome this restriction. Recognizing automatically assessable features can help teachers to create educational models, where automatic tools let teachers concentrate their work on the learning issues that need student-teacher interaction the most.

Several automatic tools for both static and dynamic assessment of computer programs have been reported in the literature. This article promotes these issues by surveying several automatic approaches for assessing programming assignments. Not all the existing tools will be covered, simply because of the vast number of them. The article concentrates on bringing forward different assessment techniques and approaches to give an interested reader starting points for finding further information in the area. Automatic assessment tools can be used to help teachers in grading tasks as well as to support students' working process with automatic feedback. Common advantages of automation are the speed, availability, consistency and objectivity of assessment. However, automatic tools emphasize the need for careful pedagogical design of the assignment and assessment settings. To effectively share the knowledge and good assessment solutions already developed, better interoperability and portability of the tools is needed.     

The Kansas Family and Children's Trust Fund: funding prevention programs in the eighties

The Kansas Family and Children's Trust Fund is an innovative approach to developing funding for community-based family violence prevention programs. Using a legislated trust fund which generates money from marriage license fees, the program has been developed based on three assumptions. First, funding at the federal level for programs to prevent family violence has probably reached its peak and has never been sufficiently secure as to allow for continuity in prevention programs from year to year. Second, there is a trend toward allowing local communities to assume a greater portion of the responsibility for developing social welfare programming. Third, in the long run more can be accomplished with a small amount of money given to a community-based organization which efficiently uses volunteer time than a larger amount of money given to an agency which has a large infrastructure to support. Information on the procedure utilized to enable passage of the Trust Fund legislation is included as well as a discussion of issues that arose in the legislation process. In addition, an explanation of the current funding procedures for accessing Trust Fund moneys is given along with examples of the types of programs that have received funding. Finally, examples are provided of similar approaches that have been used in other states as well as a call for additional innovative approaches to providing funding for child abuse prevention programs.     

Learning Prolog in a schema-based environment

A set of basic construct Prolog schemata are presented as the basic constructs of a structured Prolog for recursive list processing. Prolog schema hierarchies are given that group classes of Prolog programs within each of the basic construct Prolog schemata via most-specific schemata which high-light their similarities and differences. A schema-based instructional approach based upon this classification of Prolog programs is provided as a method of introducing recursion to novice Prolog programmers. The incorporation of this approach to teaching recursive Prolog programming in an intelligent tutoring system is presented. Finally, a schema-based Prolog programming environment embedding this tutoring system in addition to a standard Prolog development system is proposed which promotes the acquisition and use of structured programming constructs in Prolog.     

我国本科层次教师教育专业人才培养方案研究

通过对30所院校的192份本科层次的教师教育专业或师范专业人才培养方案的分析发现,当前师范专业培养人才的类型、胜任工作类型和适于任职单位都呈现出多样化特点;不同培养方案对培养目标和培养规格应该包括哪些内容没有形成一致的意见;培养方案对教师培养的认识存在差异,尤其是对未来教师需要掌握哪些知识、能力、职业道德存在不同的理解,对未来教师是否需要掌握这些内容也有不同的认识;培养方案没有借鉴当前教师培养、教师知识的研究成果。本研究对培养方案的改进提出建议。     

程序设计语言在计算机学科研究中的位置

程序设计语言是用于编写计算机程序的语言。在计算机学科研究中,无论是理论研究还是技术研究的成果,最终目标要体现在计算机软件产品的程序指令系统应能机械地、严格地按照程序指令执行,而程序设计语言的特性和编码途径会对程序的可靠性、可读性、可测试性和可维护性产生深远的影响。目前,人和计算机通信仍然必须使用人工设计的语言,即程序设计语言,而几乎所有的计算都需要程序设计语言才能完成。     

Software‐Realized Scaffolding to Facilitate Programming for Science Learning

Abstract

Programming is an activity through which students can learn about other domains, but the difficulty of programming diminishes its usefulness as a learning activity. One approach to facilitate the use of programming for learning is to view programming as a skill like those taught through apprenticeships, and to use the apprenticeship concept of scaffolding to facilitate doing and learning through programming. Scaffolding means providing modifiable support (through fading) that communicates process, coaches, and elicits articulation. Software‐realized scaffolding embeds scaffolding in a computer‐based environment. Emile implements software‐realized scaffolding to facilitate student learning of physics by facilitating students building computer‐based models and simulations. In this article, I present Emile's features as examples of software‐realized scaffolding, and I present the results of an evaluation of Emile's effectiveness. Students were able to use Emile to create fairly sophisticated programs and gained a qualitative understanding of kinematics in the process.     

Detecting Unobserved Heterogeneity in Latent Growth Curve Models

Growth mixture models combine latent growth curve models and finite mixture models to examine the existence of latent classes that follow distinct developmental patterns. Analyses based on these models are becoming quite common in social and behavioral science research because of recent advances in computing, the availability of specialized statistical programs, and the ease of programming. In this article, we show how mixture models can be fit to examine the presence of multiple latent classes by algorithmically grouping or clustering individuals who follow the same estimated growth trajectory based on an evaluation of individual case residuals. The approach is illustrated using empirical longitudinal data along with an easy to use computerized implementation.