The problem is all inside your head she said to me,
The answer is easy if you take it logically,
I'd like to help you in your struggle to be free

Paul Simon

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Monday 22 September 2014

It's Hard...

Computer Science; it's hard, and here's why.

Imagine a spreadsheet.  A spreadsheet that is being developed by the manager of your friendly local cinema.  He has been told to make a spreadsheet to predict how many seats he needs to sell on a Saturday night to break even.  It wouldn't be a huge surprise if the manager couldn't do this, despite spreadsheets routinely being used by school children.  The difficulty is that the problem is definitely at the top end of Bloom's.  It's hard.

First of all the problem has to be broken down into more manageable parts, perhaps the income and expenditure.  Let's look at the income in a little more detail.  There is ticket sales.  There has to be a prediction of the number of tickets that are likely to be sold.  This prediction could be based on how well similar films have done; the time of year and the weather amongst other factors.  The manager has control of the ticket prices so now it should be a simple matter to work out income from the tickets.  But how many of these punters will buy popcorn? Or coke?  This will require more analysis.  What about advertising?  You can see that modelling the income is not straight forward, and I haven't even touched on the expenditure.

Even at Key Stage 3 level, it's hard.  Using the scenario above, a KS3 example spreadsheet might automatically add up the number of seats occupied by adults and the number of seats occupied by children.  An instruction might be, "Add a formula to the spreadsheet to work out the total number of seats sold."  At first sight you might think that that the instruction is fairly straight forward but learners fail at several levels.  First they need to be able to understand the question.  Some lack the literacy skills needed to do this.  Then they need to analyse the question to work out the arithmetic required to solve the question.  Then they need to add a further layer of abstraction to translate the arithmetic into a formula using cell references from the existing spreadsheet.  This one seemingly simple instruction must fit well up on Bloom's taxonomy.  In other words, easy spreadsheet tasks are hard!  They rely on well developed skills from other areas, plus an extra layer of abstraction.

Footnote: If I was writing this post last year I could have written exactly the same thing, but with a different first line - ICT; it's hard, and here's why.  It is curious that in society at large, ICT is seen as 'easy' and Computer Science is seen as 'hard'.  I cannot understand this.  Is it because the majority of the population use computers and think that they are doing ICT but are bewildered about how they work?

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