All about A level Computer Science

What's A Level Computer science about?

A level Computer science is split into two complementary sections, programming and theory.  On the programming side of the course, students can learn a programming language (chosen by your teachers from C#, Java, Pascal/Delphi, Python and VB.Net).  You will cover  the fundamentals of programming, data structures, algorithms, and object-orientated programme design.

The theory side of computer science teaches about the internal workings of a computer, right down the basics of how all data is stored using binary, whether that data consists of numbers, text, pictures or even music.  It goes on from there to cover aspects of computer architecture, showing exactly how data is accessed from main memory using assembly language instructions and the fetch-execute cycle.

As well as covering programming the course aims to promote good programming practices such as avoiding global variables, sensible variable naming, structured programming, good re-use of code through procedures and functions, and proper commenting of code.  It also covers higher level concepts such as the social and legal impact of computers, and how to go about breaking down a big problem into individual programmable steps.

What sort of work is involved?

The A level Computer science course consists of work towards two exam papers, both worth 40% of the whole, plus non-exam assessment worth 20% which will typically be done over a period of about 3 months.

The first exam is a programming test, which some exam boards, such as the AQA,  like to do using an on-screen exam.  This will test your ability to solve problems as much as it will test your technical knowledge of the programming language you have learned.

The second exam tests theory and is a written exam.  Questions are designed to test your knowledge of computer systems, how they are formed, the social and legal parts of computing, communication, networking and databases.

For the non-exam assessment you  pick your own project which must have a significant programming element.  You will create a program to solve a problem, such as writing a computer game, making a mobile phone application or doing an investigation into machine learning.  There is no restriction on programming language used in the project, so you could use Swift, Objective C, C++ or any other language you wanted to do your project.  However,  drag-and-drop languages, such as Scratch, are not allowed. When writing coursework you won’t just be expected to produce working code, but will be expected to write good, well structured working code.

What background do I need?

To do A level Computer science it is not essential to have done computer science at GCSE, though it is advisable to have done some practice of programming in your own time.  The course has a significant programming element and those who have no previous experience of programming often find it very challenging.

You ought to have at least a B-grade in mathematics.  There are several topics that require the ability to reason logically and apply mathematical and logical processes to solutions.  It is likely that if you find mathematics enjoyable and interesting then you will also like computer science.

Where can it lead?

A level Computer science is naturally a strong subject to take if you wish to go on to do computer science at degree level, and although most computing-based degree courses don't require Computer science A level there are a number of software engineering courses which do.  There are also other degree courses such as information technology and information systems which will be served well by a Computer science A level.

After university, there are numerous interesting fields of study and professions that you can go in to.  Computer science will lead on to robotics, artificial intelligence, machine learning, cloud computing, big data processing, networking, ethical hacking, computer game development, home automation or even teaching.  So much of the world uses computers nowadays that having a good understanding of how computers work and how to program them will set you up for success in many strands of life.

Numbers of computers are also increasing in many developing countries too, meaning that your skills in computer science will be very portable.  The most popular programming languages in the world are based on the English language using statements such as for, while, if, else, repeat, so studying computer science in an English speaking college will give you a good foundation if you wish to travel and find a job working with computers in another country.

One year course?

Due to the coursework element, A level Computer science is very difficult to do in one year.  To succeed you would need to already have a firm grasp of programming such that you could begin the year doing coursework and getting it out of the way, leaving you enough time to cover the theory before taking exams in June.

There is an AS-level available which covers most of the topics but not in as much detail as the A-level.  Like the A level, there are two exams, one of which is programming and the other theory but they are each worth 50% of your overall grade.

Assessment

As previously mentioned, A level Computer science consists of two exam papers, each 2 1/2 hours long and each worth 40%. The remaining 20% comes from your coursework.

The coursework assesses your ability to take on a significant problem and produce a solution to it.  Despite the large programming element, you will actually be marked on the documentation you produce.  This will typically consist of an analysis, designing the solution, annotated code showing your finished solution, tests demonstrating that your solution works and an evaluation.

Written by Dave Wright, of Cambridge Centre for Sixth-form Studies