12 November 2012

Beware of Excel Histograms

Update in 2018 I am happy to say Excel 365 has the facility to make acceptable and dynamic histograms. Well done Excel! Here is a link to a video to show you how: Original post in 2012 Excel histograms are a disgrace. Microsoft should be embarrassed to have them associated with their ubiquitous and generally wonderful spreadsheet, Excel. I have previously posted on how useful and versatile Excel is for enabling people to bypass the number crunching, and get to the ideas behind statistics. This is mostly true. But the histogram add-in should come with a health and safety warning. […]
29 October 2012

Which type of error do you prefer?

Mayor Bloomberg is avoiding a Type 2 error As I write this, Hurricane Sandy is bearing down on the east coast of the United States. Mayor Bloomberg has ordered evacuations from various parts of New York City. All over the region people are stocking up on food and other essentials and waiting for Sandy to arrive. And if Sandy doesn’t turn out to be the worst storm ever, will people be relieved or disappointed? Either way there is a lot of money involved. And more importantly, risk of human injury and death. Will the forecasters be blamed for over-predicting? Types […]
15 February 2012
Messy girl

Giving students dirty data

Dirty data is real data as it is collected before someone gets hold of it and takes out the tricky bits. You won’t find dirty data in textbooks. Dirty data is what real researchers have to deal with. And even amateur researchers and students doing real-life projects will have to deal with dirty data. Yet not much is said about dirty data, and what to do with it. Elements of dirty data Mistakes – people put down the current year for their date of birth, give their weight in the wrong unit, put an extra decimal point. Missing data – […]