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The errors in question has nothing to do with inherent flaws in Excel (beyond, perhaps, the difficulty of reviewing Excel code). The problems were in decisions

The errors in question has nothing to do with inherent flaws in Excel (beyond, perhaps, the difficulty of reviewing Excel code). The problems were in decisions made to exclude data, arbitrary "analysis" with no basis in statistics or common sense (19 - IIRC - years of data from England were given the same weight as one year of data from New Zealand), and an egregious formula error that simply ignored several rows of data.

mbetter 14y ago
I would suggest that in a situation like this, "the difficulty of reviewing Excel code" is even overstated. The direct dependencies of any cell are discoverable with trivial effort.
tadfisher 14y ago
To be fair, Excel's concept of a weighted average has no basis in statistics or common sense, as I have seen in a couple of published works. Here's a tip: if your results are reproducible only in Excel, something is terribly wrong.
- podperson 14y ago
  I don't think they were using Excel's weighted average function in this case but simply averaging filtered figures per country and then averaging the averages. This has no statistical basis, but it's not Excel's fault
Toenex 14y ago
beyond, perhaps, the difficulty of reviewing Excel code This has always been one of my concerns when Excel is used much beyond 'electronic squared paper'. The interwoven data and code nature of the tool makes testing and verification more difficult - certainly not impossible but going against the grain of the tool. Excel is used by a diverse range of people, many of whom have limited software skills and could do with a tool that enforced the right behaviour. Also I think this shows the need for openness when people make such important claims based on data. Particularly in this case where all the data and calculations could easily be zipped up and put on a website.
- james1071 14y ago
  Agree-the fundamental problem is that formulae are copied from cell to cell. It is so easy to make a mistake on a big spreadsheet. A much better approach would be to write user defined functions.

mbetter 14y ago

I would suggest that in a situation like this, "the difficulty of reviewing Excel code" is even overstated. The direct dependencies of any cell are discoverable with trivial effort.

tadfisher 14y ago

To be fair, Excel's concept of a weighted average has no basis in statistics or common sense, as I have seen in a couple of published works. Here's a tip: if your results are reproducible only in Excel, something is terribly wrong.

podperson 14y ago
I don't think they were using Excel's weighted average function in this case but simply averaging filtered figures per country and then averaging the averages. This has no statistical basis, but it's not Excel's fault

Toenex 14y ago

beyond, perhaps, the difficulty of reviewing Excel code This has always been one of my concerns when Excel is used much beyond 'electronic squared paper'. The interwoven data and code nature of the tool makes testing and verification more difficult - certainly not impossible but going against the grain of the tool. Excel is used by a diverse range of people, many of whom have limited software skills and could do with a tool that enforced the right behaviour. Also I think this shows the need for openness when people make such important claims based on data. Particularly in this case where all the data and calculations could easily be zipped up and put on a website.

james1071 14y ago
Agree-the fundamental problem is that formulae are copied from cell to cell. It is so easy to make a mistake on a big spreadsheet. A much better approach would be to write user defined functions.