17 December 2012

Organising the toolbox in statistics and operations research

Don’t bury students in tools      In our statistics courses and textbooks there is a tendency to hand our students tool after tool, wanting to teach them all they need to know. However students can feel buried under these tools and unable to decide which to use for which task. This is also true in beginning Operations Research or Management Science courses. To the instructors, it is obvious whether to use the test for paired or independent samples or whether to use multicriteria decision making or a decision tree.  But it is just another source of confusion for the […]
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 […]
3 December 2012

One year on!

I have been blogging for just under a year now, and have written over 50 posts. There have been over 30,000 hits on the blog, and some very helpful comments. I’ve had a lot of fun, and there is something exciting about thinking that other people might value my thoughts and writing. Thank you all those who have left comments or emailed me. I spent my morning making up a summary page so that it is easier to find your way around previous posts. It is in the “Collected Works” tab above. In order to do this I had to […]
26 November 2012

Careers advice in Mathematical Sciences

Mathematics teachers as Careers advisors What can you do if you are good at mathematics? Become a maths teacher, of course! I wonder how many of our students are aware of what wonderful and exciting career opportunities are out there for the mathematically competent, including being a mathematics teacher. I also wonder how many teachers of mathematics, statistics and operations research are telling their students of the different possibilities. I always loved maths at school and was good at it. I liked teaching, so I decided to be a maths teacher. Along the way, at university, I discovered computer programming […]
19 November 2012

The Sound of Music meets Linear Programming

“Let’s start at the very beginning – a very good place to start. When you read you begin with A, B,C!” When you do statistics you begin with…probability? the mean? graphs? Begin at the end But really, is the beginning a very good place to start? Sometimes, we need to begin at the end. And sometimes we need to go back before the beginning. Always we need to think about where to begin, because it is seldom obvious, and copying what other teachers and textbooks have done is often a bad idea. Linear programming Take Linear Programming, the flagship technique […]
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. […]
5 November 2012

Probability, Perception and False Positives

An understanding of probability empowers people to make informed choices in matters of great importance, including health screening, insurance, major weather events and terrorist threat. Unfortunately it has been shown that this understanding of probability eludes even some of our most educated professionals and decision-makers Perceptions of Probability and Risk There is a considerable body of work studying people’s perceptions of probability and risk, particularly by Amos Tversky and the Nobel prize-winning Daniel Kahnemann. This has uncovered many systematic errors humans make in judging the relative probabilities of uncertain events. The brain’s tendency to find patterns results in heuristics or […]
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 […]
22 October 2012

The Golden Rule doesn't apply to teaching

Problems with the Golden Rule The Golden rule is fundamental to most human cultures. It reads, approximately, “Do unto others as you would have others do unto you,” or “Treat others as you would like to be treated.” It sounds good at first glance, and I hesitate to argue with the wisdom of God and most cultures but I propose that the Golden Rule fails if applied mechanistically. I’ll explain with some examples, and show why this is important in teaching, especially subjects like statistics and operations research. Not long after after we were married, my husband was lying sick […]
15 October 2012

Optimal instruction in Statistics and Operations Research

Optimise everything! I had a colleague who believed that everything could and should be optimised. He had a diet Linear Program which he used to plan his meals to provide optimal nutrition. Unfortunately the Linear Program didn’t seem to have a constraint to ensure the food was palatable, and he would eat combinations like sardines, broccoli and sunflower seeds for lunch. My colleague also believed that there must be an optimal way to teach, that would maximise the learning outcome. I am doubtful that there is such a thing, bearing in mind the diversity of human experience. However I like […]