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The Wall

We know that spreadsheets are important for many applications, including informing decision making. We also know that spreadsheets have real and substantial risks.

Therefore, an obvious question is: Why is spreadsheet practice generally so poor?

Spreadsheets demand serious attention

The answer is that we tend to treat spreadsheets as being simple, below the threshold that demands serious attention. This is especially true for managers, who typically consider spreadsheets to be a simple tool. However, they are misguided. In practice, many spreadsheets are sophisticated applications that we use in complex ways.

Developing and using spreadsheets is often far from easy – as anyone who has struggled with a spreadsheet will attest. Yet, once a spreadsheet is complete, we treat it as if there's nothing complex about it at all.

A key issue is that the formulae are hidden behind the spreadsheet's presentation layer. Nicely formatted values may disguise a tangled mess of convoluted and complex formulae. We tend to equate nice presentation with good design, but often that is not the case.

Even simple spreadsheets have errors

This point is reinforced by research showing that even simple spreadsheets often contain errors. In one experiment:

  • Students developed and debugged a spreadsheet model from a word problem.
  • This model consisted of a bid to build a wall.
  • The problem was designed to be relatively simple and domain-free.
  • In the development phase, 38% of the models contained an error.
  • In a debugging phase, subjects tried to debug their own models. Only 16% found and corrected their errors.
  • The conclusion was that even with a simple model, development and debugging are problematic.

This exercise, known as "The Wall Problem", has been replicated many times, with similar results.

Because most managers are unaware of the risks, they do not give spreadsheets the attention that their importance deserves. This lack of attention allows the use of poor practices, further increasing the already largely unrecognised risks.