I have seen a lot of toing and froing on social media recently about the merits of different exam boards and who is going with which specification and why. Unfortunately, I feel that many teachers are misleading themselves and haven’t really considered the full facts before making a decision.
Perhaps they are basing this on their past experiences with older qualifications but it is now time to think again.
It seems that vocational qualifications are still in the minority compared to GCSEs but I find it interesting that many people are basing their judgment on what the non-examined assessment is like rather the exam material. I don’t have issue with departments who feel it is in their pupils’ best interests to choose a coursework-heavy qualification but I am concerned that those sticking with the GCSE are still in the mindset of the old 60/40 model of assessment where coursework allows you to neglect exam preparation.
If I were still teaching in school, as I suggested here, I would choose the AQA specification. The clear detail provided seems to put some off (something about too much to teach), but if we are considering that the primary mode of assessment is a written examination, surely teachers want all the details of the subject content as possible.
If there is a lack of detail then we have a situation like June 2015 where pupils struggled with the OCR GCSE Computing paper. The term opcode used in one of the questions threw both teachers and pupils alike. It wasn’t that the concept was difficult or wasn’t in the specification, rather the terminology used hadn’t appeared in previous exams, the course textbook or in the specification.
By way of comparison I looked at the specifications for the four exam boards offering a computer science GCSE. I picked data compression as you can make this topic as simple or as complicated as you like. What I wanted to consider was how much detail as a teacher I need to go in to and which compression techniques could come up in the exam.
- need for compression
- types of compression:
3.3.2 understand the need for data compression and methods of compressing data (lossless, lossy) and that JPEG and MP3 are examples of lossy algorithms
3.3.3 understand how a lossless, run-length encoding (RLE) algorithm works
- Explain how lossy and lossless data compression algorithms are used.
- Calculate compression ratios.
Then lastly AQA (less the additional information column that provides further clarification for each point):
- Explain what data compression is.
- Understand why data may be compressed and that there are different ways to compress data.
- Explain how data can be compressed using Huffman coding.
- Be able to interpret Huffman trees.
- Be able to calculate the number of bits required to store a piece of data compressed using Huffman coding.
- Be able to calculate the number of bits required to store a piece of uncompressed data in ASCII.
- Explain how data can be compressed using run length encoding (RLE).
- Represent data in RLE frequency/data pairs.
I would suggest that only Edxecel and AQA specifically mention names of compression methods that should be investigated. To me that is specific detail that I would want to know as a teacher delivering this topic.
Others have pointed out in the past that some exams seem more accessible than others, or that different exam boards offer addition supporting guidance, so I wouldn’t make this the sole reason for choosing which exam board to go with.
Similarly, don’t just pick the thinnest specification because it has the least content. It may actually be more involved than you think.