New Higher – Negative Numbers

  • speirs
    Participant

    Hi, can any one advise if negative numbers are retained within the new higher. I can see no reference in the Mandatory Content document unless SQA operate on the basis it is part of Real numbers. After seeing a question relating to negative numbers in a sample paper I wish to clarify if it needs to be taught or not?
    cheers
    Jean

    Elizabeth Whaite
    Participant

    The first question in the new higher was converting a negative integer into binary. Although the arrangements don’t specifically state two’s complement the candidates do have to know binary representations of integers.

    Tony Harkins
    Participant

    I think a general rule of thumb is to aim for roughly the same level as the old Higher. For example, if Int2/Nat5 expects pupils to convert positive integers to binary or vice versa then, I’d expect Higher pupils to be able to describe one way of representing negative numbers. If you describe signed bit or 2’s complement, both would be correct since neither is explicitly named in the course assessment spec. Similarly, they must know how graphics, sound and video are stored so I would expect a higher level of understanding than in N5 e.g. some idea of MPEG compression for video, perhaps some idea of RLE or LZW compression for bitmaps, i.e. the level of the old higher multimedia unit. When there is a single mention of operating systems, I’d still go into some idea of file mgmt, memory mgmt etc. A lot will be guesswork until we have a few more papers to look at, particularly on newer content like cloud storage, virtual machines etc.

    speirs
    Participant

    Thanks Tony, that gives me a few additional things to think about and aim for.
    cheers
    Jean

    a1an.robertson
    Participant

    I think that it is very unfair that we are expected to interpret the assessments spec. in this way. As we all know, the new course is in effect a hybrid of the old computing higher and the information systems, how are we then expected to be comfortable making these types of judgement when many (most?) have only been teaching one course at that level. In my case, I’m concerned about what am I going to teach at too low a level in the Information Systems course.

    A couple of years ago I attended the CASS conference in Glasgow and the question arose about negative integers with respect to N5. The answer we were given was that if it does not appear in the spec it can’t appear in the exam. In other words, we were told, negative numbers are not in the exam at N5. Why should this change at higher?

    Peter Thoresen
    Participant

    Have a look at the Course Assessement Specifications for some other subjects.

    For Higher Computing we get get 4 pages of bullet points, Higher Biology has 10 pages of dense text (what appears to be a decent set of revision notes).

    Read into this what you will.

    Enrico Vanni
    Participant

    It is not unfair – it is damn criminal! This is the sharp end of CfE – what is being paraded as ‘professional judgement’ and ‘choice’ actually amounts to teachers crossing their fingers and hoping they have covered points in sufficient depth and students having to read the minds of the exam setters. It might seem a small point and ‘obvious’ to Computing teachers that negative numbers/two’s complement ‘used to be’ part of Higher (and yes there’ll be those who will say we should not be teaching to an exam), but not everyone teaching new Computing Science will have the benefit of this experience and it is wholly inappropriate in the light of the merger of Info Systems and Computing to assume otherwise.

    Specific guidance as to course content and depth should be a given. Obtaining qualifications should not be a crap-shoot.

    Higher Computing Science wasn’t so much a half-baked recipe as an ingredients list with no method when it was announced. A year on and it still is nowhere near ready for the oven.

    dbrowning
    Participant

    And there in lies one of the major problems with CfE Computing Science qualifications. The course covers some really interesting stuff but working out how we assess the practical work and what and what isn’t in the exam is a little better than guesswork given what we’ve been given. The result is that the course is difficult to teach at the correct level, is likely being over assessed by most of us and kids are potentially being turned off the subject. To me this ties in with my thread in the N5 section regarding marking of work for overcoming unit assessment criteria and the course assignment. We’ve been saying for years that more needs to be done here but for some reason in our subject it’s not happening, or not at a pace that is, in my opinion, fast enough.

    Enrico Vanni
    Participant

    The reason little is getting done is because it is very easy for those in charge to hide behind the fig-leaf of ‘professional judgement’ and ‘choice’, but the amount of detail in the other Sciences’ arrangements documents compared to the lack of detail in Computing proves there is no consistency across subjects and awards, and this itself will put pupils off choosing our subject in future when this becomes common knowledge (as it will).

    At an SQA Higher Transition Event in Glasgow a couple of weeks ago Raymond Simpson replied with the words “that is a good question” time and time again to points raised by the delegates regarding the new Higher CS, particularly with depth and detail. It is worrying that specific issues are being identified with the courses, their content and assessment by those tasked with delivering them, but it appears little or no thought or activity is being put into addressing these issues by those who ‘should’ have the answers. The SQA seem to think that sticking rigidly to their timetable for issuing updates (which often cause as many problems as they solve) and tweaking Assessment Packs is sufficient.

    dbrowning
    Participant

    Well see my other post in N5 forum, I emailed Dr Janet Brown, chief executive of SQA regarding my concerns. Maybe if more people add their voice to this it will carry more weight.

    Janet.brown@sqa.org.uk

    Nicky Pasternak
    Participant

    I wholeheartedly agree with these comments -re the lack of clarity on depth of treatment with the courses. We are having to wait to see the actual exam papers and guess what to cover.

    I recall the CASS conference comments which a1an.robertson referred to where I asked about what we were to teach about the representation of integers.

    N4 states
    The use of binary to represent and store positive integers
    N5 states
    The use of binary to represent and store integers and real numbers

    From the above it would be reasonable to assume that negative integers would be included at N5. This, I am sure, is why the textbooks and revision guides for N5 published include two’s complement.

    At the meeting, however, we were told by the Principal Assessor that negative integers would NOT BE ASSESSED in the final written exam. This begs the question about what the difference is between N4 and N5 and is symptomatic of the underlying problem which many of us are highlighting.

    The Current Specifications do not give us enough detail about content and depth of treatment. It is up to us to make this clear to SQA at the highest level. Dave Browning’s plea for us all to contact
    Janet.brown@sqa.org.uk is very important.

    A campaign by CAS Scotland similar to the one about internal assessment and marking would be very helpful too. Can we, as a body, make an official request to SQA to provide greater clarification about depth of treatment? This would lend weight to our cause.

    There is a lot of good in the new courses and they can be successful but we do need action on this point.

    Andy McSwan
    Participant

    All very good points, the lack of clarity is a big issue. What I would say to you Nicky is that CAS Scotland is run by volunteers, since you feel strongly about this (and this goes to everyone else here) why not join the cas Scotland group and organise it (you would get lots of help I’m sure).

    Remember there is no them, only us!

    dbrowning
    Participant

    Fair point Andy and I should probably think about putting my money where my mouth is and joining CAS to effect change. Of course there are issues for us all like the business of life/families etc. but I think CAS is a good vehicle for moving things forward.

    At the same time I would note the following:

    1.As I said in another post we’ve been telling the SQA about these issue for years, since the first N4/5 meeting from what I remember, and there’s not been much change in that time.

    2. People are paid by the SQA (by the fees paid for exams presumably) to organise these courses and I genuinely wonder what they are doing with their time. Most of us have had to teach our classes, do marking, write reports and all the other day to day things that come with being a teacher and on top of that we’ve all had to separately create new materials for these courses in-between all the other things we do. For many this has taken up a large amount of holidays/weekends/evening and then we have the assessment burden. Thus while I understand your point about joining CAS I feel sorting this out should not be yet another thing that falls to teachers to fit into their already busy timetable. I don’t pay a plumber to fit a new bathroom in my house and then when it’s not done right I pay them and fix it myself. I either get them to fix it and pay them or I don’t pay them and fix it myself.

    Peter W Donaldson
    Participant

    Hi Nicky, it would be a good idea to make a comparison between the Higher Computing Science course assessment specification and some of the other sciences. However it needs one or two people willing to step forward to carry this out.

    We’ve already met with the core live team responsible for the new Higher Computing Science to pass on the research we carried out on this issue and they have said they will seriously consider moving to external assessment for session 2016/17 or the session afterwards. When the volunteers who put this together have managed to grab some time we will post up a summary of this research to the CAS Scotland group on Compednet and the cas.scot website. If we had a similar piece of work on the level of detail in the assessment specification then that could also be passed on.

    As Andy said we’re all volunteers with anything we carry out such as views on assessment, create such as our recent briefing paper for MSP’s or organise such as the CAS Scotland conference done in our own time. There are still some big issues that affect us all at the moment with quite a few still outstanding but at least we’re now able to speak with a coherent voice. It’s much harder to ignore wide-scale research of many Computing teachers particularly as we’ve also forged connections with many other education and industry groups now.

    A major issue for us is that a large percentage of the public don’t understand this area and a large number of our colleagues at all levels don’t either. Although many of us have quietly fought to be heard in our schools and local authorities there’s still not enough public awareness of what the benefits are for learners both immediately and for their longer term prospects. Our argument shouldn’t just be an economic one, or about just technical skills but should also be about the wider benefits of an education in Computing Science. I believe we’ll get there but it’s going to be challenging for a few more years yet.

    Nicky Pasternak
    Participant

    CAS is the best thing that has happened to Scottish Computing Science Education since I started teaching this subject 29 years ago. I have been a member of it since its inception and fully appreciate that it is run by volunteers who do a marvellous unpaid job in putting forward our subject and fighting our corner at all levels.
    I am well aware that there is no them and us, Andy and Peter, and was not aware of any criticism of CAS in my earlier post.
    On the contrary, it is the collective and cohesive nature of CAS which would bring pressure to bear on the SQA with a simple communication to Janet Brown saying that CAS Scotland members have serious concerns about the lack of clarity and sufficient detail for our subject in the CFE documents. As Dave Browning says, it is the SQA that needs to do the work on this, not us.

    We have been told at various SQA events over the last few years that the Computing Science team was not allowed to put in the level of detail that they wanted. The SQA hierarchy wanted to give teachers much more freedom. The “progress” of CFE has given us an exam out of 90 and and an internal assessment worth 60. Big change? Lot more freedom?
    It is clear that the lack of detail is making it difficult to teach and to assess. I would not have wanted to make up this year’s SQA exam paper. This is a problem created by the SQA, not by teachers. The comparison of the course assessment specifications between ourselves and the other sciences can be done by the SQA. The “them” is the SQA hierarchy in this case. It is they who dictate the policy on this one.

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