Computational Thinking Guided Programming Training for Oversea Students with Diverse Computer Litera

www.jitae.org Journal of Information Technology and Application in Education Volume 4, 2015 doi: 10.14355/jitae.2015.04.008

Computational Thinking Guided Programming Training for Oversea Students with Diverse Computer Literacy Skills Cong Cui1, Ualikhan Dossetov2, Songjie Wei3 Division of Informationization Construction and Management, 2,3School of Computer Science and Engineering

1

Nanjing University of Science and Technology, Nanjing 210094, China *1

cuicong@njust.edu.cn; 2ualikhan@njust.edu.cn; 3swei@njust.edu.cn

Abstract Introduction‐to‐programing is not only an academic course. It serves as a prerequisite to related courses in computer science.

Coding in correct language grammar and syntax is only one part of a successful programing process, and we should never neglect the underlying problem solving task when programing. Teaching programing is especially challenging to students with diverse computer literacy and even different education and learning culture. In this paper we outline the challenges when teaching an undergraduate class of mixed oversea students. We present a new design of programing course leveraging more on hands‐on sessions with programming exercises, context and project. We help students go through programming process as interpreting and solvingproblems in computer context. Students after the class will achievenot only satisfying programing capability, but problem solving skill, and enthusiasm and confidence in further study in computer science major.

Keywords Computational Thinking;Programming Course; Oversea Students

Introduction Many course syllabuses and teaching methodologies have been developed for programming education to undergraduate students[2, 3, 6, 8]. Many expect students with some quantity of prior computer experience and knowledge. Some teach students the coding techniques by treating computer programming as merely a process of solving problems with computer aid. In 2014 fall, Nanjing University of Science and Technology (NUST) had its first class of oversea students enrolled in the Software Engineering program. These students, from Asian, European and African countries, have diverse prior education levels, and with different computer usingexperience. Some joined this program only because of the available financial sponsorships. Therefore, the Computer Science School at NUST decided to build a new ”Introduction to Computer Science and Programming” course, to introduce to students the fundamentals in computer literacy, to present the principle of computation, and to teach students to analyze and solve problems within the context of computer science. The course migratesthe oversea first‐year undergraduates from computer amateurs to compute professional candidates, and teaches them how to think computationally[10].

We present the design principles and syllabus of this new computer programming course tailored for oversea undergraduate students with diver computer literacy and education levels. Instead of focusing only on the syntax and semantics of a programming language, we adapt the computational thinkingmethod in the teaching process to help students gain general skills in analyzing and solving problems with appropriate abstraction and decomposition, where the programing language itself is just a tool to format and visualize the process and to express the solution.

The new course wasdeliveredduring the 2014‐2015 academic year for a mixed international class of 31 undergraduate students. Fig. 1 shows the student distribution by nationalities. The authors of this paper acted as the lecturer, the lab exercise tutor, and the teaching assistant during the course, and have obtainedrich first‐hand experience on designing and delivering a computer and programming introduction course targeting international

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undergraduate students with diverse or even no computer literacy skills.

FIG. 1 DISTRIBUTION OF STUDENTNATIONALITIES

Challenges Table 1 shows a statistics on class with31 students. All are recipients ofsome scholarships from the Chinese government, which impliestheir competitiveness on English language skill and high‐school education records among thecontemporaries in their own countries. With the fast prevailing of information technology products and services, and especially smartphone‐based mobile internet access, most students are familiar with computers, and have been frequently using Internet, either on PCs or smartphones. However, many still donot have clear image about what a program looks like. Only five studentsonce tried to compose or modify program source code, and had experience to compile and run it.

TABLE 1SURVEY OF STUDENTS’ COMPUTER USINGEXPERIENCE AND ENGLISH LANGUAGE SKILL (TOTALLY 31 STUDENTS)

Computer Using

18 proficient, 7 familiar, 5 limited, 1 none

Internet Using

22 frequent users, 9 occasionally

Programming Experience

26 none, 4 amateurs (C, Pascal, Basic), 1 experienced (Fortran)

Pre‐college Education

28 from high schools, 2 from technical schools, 1 from community college

English Language

16 with good English skills (speaking, listening, reading), 12 fair, 3 limited

Limited English skill is the students’ anotherweakness. None of them are native English speakers. Half of the class hasdifficulties, or at least has not enough patience to read English textbooks or lecture slides.

So we decided to rely less on lectures or textbooks, but to provide more samples and hand‐on exercises. We utilizedtheir easy access to Internet resource, and referred them to various online documents and demos.

Course Design Principles We first identifying all the essential knowledge and skills that we expect students to master. We keep reminding ourselves this course, as the first programing course in curriculum, makes more sense to educate students on what computer programs can and cannot do, and how the can‐do parts are really done with clear, rational and repeatable steps. With the following course objectives, weusedthe backward process designing of the course[9].

Training Students onComputation Thinking Method Computational thinking is not thinking like a computer, but rather as a computer professional withprofound understanding of the fundamental concepts, algorithms and procedures in computer science, and being able to apply these knowledge inanalyzing and solving complex problems in practice. We expectstudents to learn C/C++

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not just as programming languages to interact with computation machines, but as handy tools to abstract and decompose complex tasks and to discover and describe solutions. We use the course process to make students feel and adapt to the flexibility of using program language to express their imagination and creativities.

Familiarizing Students with Programming Process Many programming beginners frustrated at compiling their source code and tracking runtime errors by just keeping to change code and try again without clear though and target. Just like writing source code is more than typing on keyboard, compiling and running a program is a lot more beyond clicking relevant IDE buttons. Before a student types in any hello‐world program, we teach him/her with source code ready there, what are next steps to make it run and assure its correctness. We think for beginners, compiling precedes coding, and debugging precedes designing.

Teaching Students for Basic Programing Skills Programing in C/C++ is not only the primary section of the course content, but also the indispensable support and context of implementing other course objectives. We expect students after this course to be able to write C/C++ programs to control the behavior of a computer following steps in a problem solution, i.e. program implementation of an algorithm.

Motivating Students in Computer Science Study As Dr. Knuth once mentioned when describing the art of computer programming, programming should be feedback to programmers with both intellectual and emotional satisfaction[4]. The latter has especially significant impact on fresh programmers, those who are frequently tortured by simple but nonnegligible code errors and are easily discouraged. Having students of different cultural backgrounds with various endurance and tolerance on failure, we realize that our C/C++ course, as their first touch with computer programming, should make the students feel inspired and interest in the field of computer science. The course and its instructors should never act like a judge of student’s talent in programming, but as coaches and cheerleaders to guide students stepping into programming world with hope and confidence.

Course Syllabus and Delivery The course is designed with two sessions delivered through the first year for Software Engineering undergraduate students. In fall semester, there are 48‐hour lectures, which focus on the fundamentals of the C/C++ programming languages and the Dev‐C++ integrated development environment (IDE).C/C++ language is introduced as a tool to organize data structures and to express computation algorithms. Basic computer data structures such as arrays, linked lists, binary trees are introduced as case studies. And the popular computer algorithms for sorting and searching are discussed. While students have chance to thoroughly study the relevant topics in later course, wehope to equip them enough concepts and methods for the next‐stage programming practices.

In the second sessionof 6 weeks in spring, students utilize the learned C/C++ language to solve problems andcomplete a course project. The instructor and TA gather the class twice per week, spending two afternoons in computer labs. First, a programming problem is announced with requirements and resources. Then students work on computers to design, code and validate their solutions, with guidance and assistance from the TA. At the end of the second weekly gather, the instructor grades the solutions, and chooses one to demonstrate and discuss with the whole class. The chosen one either holds merits on its design and implementation, or shows typical mistakes.

The right way of learningprogramming is to write programs. And the good timeto understand program execution is debugging. We design and organize the followings programing problems and challenges to give students sufficient opportunities to practice their programming skills, and to train their computation thinking capability in realistic problem solving process. The first four exercises areassigned one in each week. The online contest is announced at the beginning of the second session. And the course final project is announced in the last week. We point student to online documents and manuals as references about C/C++ language and standard libraries,

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frequently used algorithms and data structures, such as cplusplus.com, and NIST data structure dictionary[1, 7]. ● Using the compiler and debugger. This exercise familiarizes students with the Bloodshed Dev‐C++ IDE. The instructor provides several files of source code with either compilation errors, runtime errors, or algorithm errors. Students are asked to use the IDE tools and functionalities such as building, setting breakpoints, tracking, profiling to identify and fix the errors. ● A calculator supporting arithmetic operations of two integers of any size. Students are required to write a program to read in two long integers and an operator (addition, subtraction, multiplication, and division) in between. The program calculates the answer and output. This exercise highlights several techniques in programing, the linked list data structure, the dynamic memory allocation, and the string‐number conversion. ● Sudoku generator and solver. Students are asked to design and implement a Sudoku puzzle generator, validator and solver. The puzzle generator can output a new problem into a file. The Validator reads a solved puzzle from a file and validates its correctness. The solver reads a puzzle problem file and search its solution. We originally want to choose some game that can be easily understood by people from different cultures, and a game without too much mathematics or strategy involved. With a quick survey, the Sudoku turns out to be popular in all the countries. ● B‐tree implementation. We provide students some preliminary training on organizing computer data with structures, and pick B‐tree as an example to practice,which is complex enough for implementation with its operation on splitting and combining nodes to keep balanced. The B‐tree data structure is also useful for the followup course project. Students may search online to download and reuse source code, which is acceptable, because we believe code reuse is a good practice in software engineering. Encouraging and training students to search, understand and reuse existing code is also a design purpose for this exercise. ● LeetCode[5] is a websitefor preparing and practicing programming interviews. It has 200 questions spanning many aspects in computer programming. All are rated based on difficulties. Users can type in source code and submit for testing online. LeetCode makes a good venue for our students to learn programming, testing and debugging, with realistic industry‐interview used programming problems. The browser‐based platform is easily accessible. Some of our students even worked on problems on smartphones in their spare time. ● Course final project. In the final project, students can work in group of 2 or 3 people to design and implement a database system. The database will store data in files, support record insertion, deletion and query.

The submitted project is evaluated based on its correctness, functionalities, and performance.

The course final grade sums up the programming exercises (40%), the online LeetCode‐based contest (20%), and the final project (40%). Table 2 showsthe grade distribution for the first two and the cumulated final. Grading symbols are converted from the 100‐point‐based scores, interpreted as “Excellent”, “Good”, “Passing”, and “Failing” respectively.

TABLE 2 GRADE DISTRIBUTIONIN 2014‐2015 ACADEMIC YEAR Grade Scale

Course Exercises

LeetCode Challenge

Final Course Grades

A (86‐100)

22%

28%

19%

B (76‐85)

35%

43%

55%

C (60‐75)

40%

26%

23%

F (<60)

3%

3%

3%

During the course, we saw a slow but steady progress of students’ programming skill. While only 57% did “Good” work in the programming exercises, which were conducted in the first 4 weeks, over 71% did well in the LeetCode

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based programing contest, and 74% received a good final grade of B and above. A good grade on LeetCode challenge implies a student’s continuous, diligent and fruitful working on LeedCode problem solving, which requires not only spending time online, but thinking in computation, and efficient coding and debugging capability. Students finished their course design project as an integrated evaluation and demonstration of the students’ knowledge and abilities to utilize computer programming tools to analyze and solve problems. We graded each student’s work based on the submitted project design report which demonstrates how the student will format and solve the problem in computational thinking, the project source code which measures the student’s coding and code organization skill, and the software functionalities and performance which reflect how students utilized the learned knowledge in practice. All except one student implemented the required functionalities and submitted, and many provided extra functionalities for user convenience, or built the system with better data structure than discussed in class for performance. These students have gone beyond of writing compilable and executable code, and using computer program to express their understanding on problems, to implement and validate their innovative solutions.

Conclusion We present our design of a new C/C++ programming course adopting computational thinking for oversea students with diversecomputer usingexperiences and cultural backgrounds. The course inspires students in computer science, to interest them in computer system and architecture, and to strengthen them with necessary programing skills and feeling.

With our last class of students moving to their second year of study, we are looking forward to more feedbacks from them and their instructors on how this course serves as a prerequisite of other courses in software engineering program, and how we can better prepare these followup computer courses for students.

References [1]

C++ Resources Network, http://www.cplusplus.com/

[2]

Cortina, Thomas. “An Introduction to Computer Science for Non‐majors Using Principles of Computation.” ACM SIGCSE Conference, 2007

[3]

Husain, Moula, and Tarannum, Neha, et al. “Teaching Programming Course Elective: A New Teaching and Learning Experience.” IEEE MITE Conference, 2013

[4]

Knuth, Donald. “Computer Programming as An Art.” CACM, Vol 17, No 12., 1974

[5]

“LeetCode Online Judge.” http://leetcode.com

[6]

Lu, Yan. “Teaching Object‐oriented Programming with Games.” ITNG Conference, 2009

[7]

NIST.“Dictionary of Algorithms and Data Structures.”http://xlinux.nist.gov/dads/

[8]

Papaspyrou, Nikolaos, and Zachos, Stathis. “Teaching Programming through Problem Solving: the Role of the Programming Language.” FedCSIS Conference, 2013

[9]

Wiggins, Grant, and McTighe, Jay, “Understanding by Design.” Supervision & Curriculum Development, 1998

[10] Wing, Jeannette. “Computational Thinking.” CACM, Volume 49, No. 3., 2006

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