31 March 2014

Teaching Confidence Intervals

If you want your students to understand just two things about confidence intervals, what would they be? What and what order When making up a teaching plan for anything it is important to think about whom you are teaching, what it is you want them to learn, and what order will best achieve the most important desired outcomes. In my previous life as a university professor I mostly taught confidence intervals to business students, including MBAs. Currently I produce materials to help teach high school students. When teaching business students, I was aware that many of them had poor mathematics […]
19 August 2013

The importance of being wrong

We don’t like to think we are wrong One of the key ideas in statistics is that sometimes we will be wrong. When we report a 95% confidence interval, we will be wrong 5% of the time. Or in other words, about 1 in 20 of 95% confidence intervals will not contain the population parameter we are attempting to estimate. That is how they are defined. The thing is, we always think we are part of the 95% rather than the 5%. Mostly we will be correct, but if we do enough statistical analysis, we will almost definitely be wrong […]
15 April 2013

Good, Bad and Wrong: Videos about Confidence Intervals

Videos are useful teaching and learning resources There is much talk about “flipped classrooms” and the wonders of Khan Academy, YouTube abounds with videos about everything…really! Even television news reports show YouTube clips. Teachers and instructors use videos in their teaching, and get their students to watch them at home, ready to build on in class time. A well put-together video can provide a different way of looking at a problem that helps a student to learn. Videos are endlessly patient and can be paused and watched at the students’ pace. (See my earlier post on multimedia for a fuller […]
18 March 2013

Confidence Intervals: informal, traditional, bootstrap

Confidence Intervals Confidence intervals are needed because there is variation in the world. Nearly all natural, human or technological processes result in outputs which vary to a greater or lesser extent. Examples of this are people’s heights, students’ scores in a well written test and weights of loaves of bread. Sometimes our inability or lack of desire to measure something down to the last microgram will leave us thinking that there is no variation, but it is there. For example we would check the weights of chocolate bars to the nearest gram, and may well find that there is no […]
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 […]