20 January 2012

Textbooks and horseless carriages

Why do my students like me and the bookreps don’t? Because I do not require a textbook for either of my large entry level courses in Statistics and Operations Research. I have found that so few students use any prescribed text, that it is pointless prescribing one. I have found other ways to engage students and help them to learn the skills, attitudes and content that I believe are necessary. The other problem was that I never found a text that aimed to develop the same skills, attitudes and content that I wanted them to. Too many of them seemed […]
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 – […]
8 March 2012

You’re teaching it wrong!

“Every year I teach them this and every year they get it wrong!”. This is a phrase I’ve heard from colleagues and from my own mouth. Then it dawned on me – if the students keep getting it wrong, maybe I’m teaching it wrong! Example of Linear regression analysis Here’s an example. In linear regression I found that students often had trouble interpreting the slope. They would get it the wrong way around, or just not get it. Every year it was the same and I repeatedly groaned at incorrect interpretations in their work. Then it struck me that maybe […]
10 April 2012

Statistics Textbooks suck out all the fun.

In 1987 George Cobb published a paper evaluating statistics textbooks. I am very grateful for it, as it alerted me to the problems with textbooks, and introduced me to the man himself, whose work I greatly admire. Cobb explains that statistics is an inherently interesting and practical subject, but that many textbooks seem to have missed that, or concealed it from the students. The discipline of statistics is inherently fascinating, applied and important. So why do so many textbooks make it seem mechanistic and abstract? I have been examining textbooks, and wonder if the writers even like their subject matter, […]
30 April 2012

Embrace Change

I love graduations. At the University of Canterbury the academic staff act as marshals, helping the graduands to be in the right place at the right time in the right order wearing the right clothes and doing the right things. I have acted as a marshal for some years and love helping people to have a good experience. I love graduations because of the accomplishment they represent, and the efforts the student, the parents and the staff have made for these young people to complete their qualifications. This graduation was pretty special, as it was the class that had to […]
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 […]
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 […]
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 […]
21 January 2013

Statistics or Calculus? Do both!

This post is prompted by two 17 year old boys, Cam and Thomas, who are about to enter year 13, the final year of High school in New Zealand. They are both academically capable, with highly educated parents. And both boys are struggling with a dilemma – should they  take Calculus or Statistics at school this year. I suspect their maths teachers are pushing for calculus, whereas their parents appreciate the value of statistics. Let’s take a look at the alternatives and see if we can help. (This makes no pretense of being a balanced view – that’s what comments […]
9 September 2013

How to study statistics (Part 1)

To students of statistics Most of my posts are directed at teachers and how to teach statistics. The blog this week and next is devoted to students. I present principles that will help you to learn statistics. I’m turning them into a poster, which I will make available for you to printing later. I’d love to hear from other teachers as I add to my list of principles. 1. Statistics is learned by doing One of the best predictors of success in any subject is how much time you spent on it. If you want to learn statistics, you need […]