14 January 2013

Assessment – a necessary evil

My northern hemisphere twitter buddies are well into the academic year, and facing the demands of grading, while here in New Zealand we are enjoying the sunshine and trying hard not to think about going back to work. However the teachers of High School statistics in New Zealand are facing (or trying not to) an interesting challenge in the coming year. They are going to have to mark (our word for grade) essays. Eek. One of the main reasons I majored in operations research, and became a mathematics teacher was that I was required neither to write nor grade essays. […]
10 December 2012

Teaching time series with limited computer access

How do you teach statistics with limited access to computers? Last century this wasn’t really an issue, at least not in high schools, as statistics has been a peripheral part of the mathematics curriculum and the mathematics of statistics has been taught as a subset of mathematics. But this is changing, and it looks as if the change is starting in New Zealand. The NZ school curriculum has leapt ahead of the rest of the world. Statistics is taught at all levels and at the higher levels of high school, statistics is taught as it is actually done in practice […]
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. […]
1 October 2012

Statistical muscle memory

I am forever grateful to the teachers at my convent high school. In my first year I was required to take thirteen different subjects, one of which was typing. At the time computers were still objects mainly occurring in science fiction and operated by punch-cards, but the nuns thought we should get a wide exposure to different subjects (just in case I decided to be a typist/linguist/artist/scientist… instead of a maths teacher). Consequently I can touch-type, a skill which has been invaluable in my career as an academic. I don’t think about where my fingers are going – in fact […]
30 July 2012

Khan Academy Statistics videos are not good

I don’t like the Khan Academy videos about statistics. But I can see why some people do. Some are okay, though some are very bad. I’m rather sorry they exist though, as they perpetuate the idea of statistics as mathematics. Khan Academy, critics and supporters Just in case you have been living under a rock, with respect to mathematics education, I will explain what Khan Academy is. Sal Khan made little YouTube videos to teach a family member maths. Other people watched them and found them useful. Bill Gates discovered them and threw money at them. Now there are heaps […]
23 July 2012

Question questions

Ooooh – new data! There is nothing like a new set of data, just sitting there in the computer, all ready for me to clean and graph and analyse and extract its secrets. I know I should be methodical in my approach, but sometimes I feel like a kid at Christmas, metaphorically ripping open the presents as I jump from graph to procedure, and back to graph again. I then have to go back and do it properly, documenting my approach and recording results, but that’s okay too. That can reveal a second lot of wonders as I sift and […]
16 July 2012

Reading graphs can be tricky

For many people, a graph is not obvious. Let me illustrate: Here are two graphs showing the results from two classes of students in some mythical test out of 10. Have a look at them and decide which one shows more variation. I won’t embarrass you by asking which one you chose. Actually I might. Try not to look at the answer before you answer this. I’ll put a pretty picture that you will have to scroll past to help you not cheat. The answer is that Class A shows more variation. This is little counter-intuitive as Class A is […]
18 June 2012

Rounding is about communication

Rounding is more difficult than first appears. It appears straight-forward. To round a number you decide how many decimal places or significant figures you need then you look one digit further to see whether the final digit stays the same or goes up. Presto – there is rounding in a nutshell. Yet my university students struggle with rounding to a surprising degree. I did a Youtube search on rounding for a video to help them, but to no avail. I wrote a script for such a video. I’m afraid it won’t be appearing any time soon as I now have […]
28 May 2012

What is the point of statistics and operations research?

What is the point of what we teach? “But what use is this?” Through the ages, maths students have whined this to their frustrated teachers. Generally the question is a diversion tactic, to avoid work, but sometimes the question is genuine. It is helpful for teachers to have an answer worked out ahead of time. (“Be quiet and get on with your work!”, isn’t really sufficient) It is preferable to present the material in such a way that the use is so obvious as to devalue the question. And it helps if the material really is useful. For many teachers […]
15 May 2012

Excel in Statistics and Operations Research

I love spreadsheets The spreadsheet package is a wondrous thing. It has revolutionized a great many processes in the office, home and scientific research. It has affected the way we think and teach. It has enabled many more people to program and to build models, without even knowing it (and sometimes very badly). And, for better or worse, Excel has become the default spreadsheet package. I love spreadsheets and I love Excel.  I first became acquainted with Multiplan and Lotus-123 in 1984 as part of my graduate degree. It was amazing to see how versatile these spreadsheets were. Since then […]