What is missing in our computer science curriculum?

From my years of experience of recruiting computer science students, it seems that universities fail to train students who can build good software. When I hire freshly graduated students, I often need to rewrite their code (sometimes from scratch) before putting the code in production. Most graduates know what inheritance and interface are, but few of them can properly choose and defend which to use. Most graduates have taken classes in “Operating Systems” and thus can talk a lot about threads and scheduling, but few actually have read books like the one from Doug Lea. They cannot be entrusted to write multi-threaded code. Most graduates memorize the visited nodes when writing a function to detect cycle in a linked list, but few of them are aware of Floyd’s cycle-finding algorithm. The funnies thing is that a lot of them think that they are writing object-oriented code because they have replaced ‘struct’ in C with ‘class’ in C++. They are yet to read a book on design pattern.

In other words, these graduates cannot use the programming languages effectively (ineffective). They cannot communicate their ideas to colleagues in their code (incomprehensible). They do not evaluate the space and time complexities of their algorithms (inefficient). They produce spaghetti code that is so difficult to modify (unmaintainable) so we have this motto in the industry: if it ain’t broke, don’t fix it. It is next to impossible to add new requirements without rewriting it from scratch (inextensible). Often when I do code review, the code looks like scribble to me. I have no way to tell whether it is right or wrong (incorrect).

I would like to point out that computer programming is a real professional that requires more than merely reading “C++/Java/C# for Dummies”. We need the programmers to know more than just the programming constructs and some irrelevant theories they never use on the job. Given a project, a competent programmer should be able to understand the problem, design efficient algorithms in terms of space and time complexities, evaluate different implementations, type in legible code, and provide systematic evidences that the code work. It is very unfortunate that universities fail to deliver students that qualify.

Why don’t universities produce good programmers? The major problem lies in the curriculum. Speaking from personal experience, I managed to finished all B.S. computer science requirements, obtained a M.S. and a Ph.D. in this field without ever taking a course in software engineering. In fact, I have never seen a university course with the purpose to teach students how to write good programs, not at the top-tier “research” universities anyway. Somehow the schools assume everyone can read the book such as “C++/Java/C# for Dummies” on their own. Consequently, most fresh graduates write dummy code.

Yes, we do programming projects for courses like Data structure, Operating System, Artificial Intelligence and etc. But these assignments aim to enhance the students’ knowledge in the particular topics. The code is never graded based on how professional it is written. Take Operating System as an example, the assignments aim to enhance the students’ knowledge on the concepts of thread and the OS scheduling algorithms but they are never designed to train students on writing good multi-threaded programs. The textbooks used in class teach about mutex and semaphore but they do not teach how to use them effectively. How many students, after taking an OS class, can design a thread-safe stack? I bet that most of them know what threads are and what a stack is, but few can design an efficient and effective thread-safe stack class.

The second problem is faculty. As a university, most faculty members hold doctorate degrees. The undergraduate courses are usually taught by newly graduated doctorate students. These doctorate students are trained to publish journal papers. Many never deliver any industrial applications in their life time (not hands-on anyway). Not only do they not know how to write good code, but they cannot appreciate how important it is to produce good code. For instance, in a Data Structure course, a professor teaches about stack, but he is unlikely to implement a thread-safe stack class for professional use. Without ever working in the industries, it is very difficult for a professor to understand the details and issues associated with using a thread-safe stack. It would even be more difficult for him to appreciate how important it is to provide systematic evidences to show that his class works and is ready for a third-party to use.

One may argue that “Computer Science” is about science so we study Artificial Intelligence, Operating System, etc. Science is about research and innovation. It is not about programming. My dilemma is that if we cannot go to computer science schools to seek qualified programmers, where should we turn to? Also, what exactly is the use of these university trained computer science graduates if they cannot write good code? After all, not everyone becomes a scientist. Most of them are engineers that code the science ideas into real products that benefit our societies.

9 thoughts on “What is missing in our computer science curriculum?”

  1. Perhaps this is still an unstable state of cultural residue that quality has not yet become the major criterion for selection.

    When the evaluation function, which might be the management and customers, does not consider the code quality at all, based on genetic theory, code quality will not improve during the progress.

    Until some new race mutated to the way of code quality oriented, which should form a positive award back to the practitioner to keep this goal onward.

    Like the test case itself, practically there is no “test case” to guard the real-life coding quality. Neither would the management do as management care the outcome more than the process. Neither would the customers do as they care the cost more than the quality.

    Maybe that is why the open source community first employing the evolution to coding quality as they can fall in love with the code, instead of struggling with the often short-sighted business goal.

  2. At the software comany I worked before, namely Microsoft, they had a testing procedure.

    At all the financial companies I worked before, I don’t rememeber the IT management ever spoke about test cases, etc., other than UAT.

    Somehow, I have a bias that IT management in the (big) financial industry is usually run by people who know nothing about IT and modern technology, (with a few exceptions). In contrast, small startups are usually run by good folks.

  3. I never understand why the management and users do not care about good quality. A very senior head of something from a very big bank once told me that he (and most people) does not care about code quality at all.

    This must be a problem in our education system.

  4. I love to read your blog. Very amazing and impressive! One question I want to ask is that how to improve one’s programming ability or skills that meet the industrial demand?
    As a analyst programmer in an ibank of HongKong, I feel exactly the same thing.

  5. Hi Derek, we will be offering some seminars on this topic in the second half of the year. Hope that you can sign up for it.

    Otherwise, getting a few good books on “design pattern” and “effective programming” will help a lot.

  6. Sure~I’m looking forward to your courses, but do I need to prepare sth. for it? I’m with IT background and not so familiar with the financial modeling of pricing. What should I do to get started?

  7. I believe company culture plays an important role here. If our peers (users/bosses/colleagues) do not respect engineering quality, and keep dumping trash into the code trunk and rushing deliveries of new features, it is impossible to maintain any quality.

    BTW Dr Li, I am a part time student and I think I will be in your course next semester… really looking forward to learn more algo trading stuff from you. I found it is quite rare to find those quantitative knowledge on books/internet.

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