about the tutorial

where and when

the tutorial has run previously as:
- half day: "Understanding Statistics", AVI98, L'Aquila, Italy, 1998.
- full day: "Avoiding Damned Lies: Understanding Statistical Ideas", CHI98, Los Angeles, USA, 1998.
- half day: "Understanding Statistics", HCI'96, London, UK, 1996.


This tutorial aims develop a 'gut feeling' for several key statistical concepts, complementing previous statistical courses by concentrating on meaning rather than formulae.

By the end of the tutorial you should be able to:
appreciate how random the world is
understand why averaging works
know why you get everywhere in statistics!
interpret significance and confidence intervals
be prepared for the pitfalls in designing HCI and CSCW experiments

not an introduction

This is not an introductory statistics tutorial. It assumes that its participants will have some experience or knowledge of statistics already. Neither is it an advanced statistics tutorial. The range of material it will cover will be similar to that the participants will have already covered as part of their studies or work. The focus is on understanding a few key concepts that make the statistics meaningful and which may prevent serious misuse.


Many researchers and practitioners in HCI and CSCW will at some time or another need to use or interpret experimental statistics. However, the correct use of statistics involves a combination of mathematics and practical know-how. Often those who have studied an introductory statistics course have learnt how to perform the requisite mathematical manipulation, but not the meaning of the resulting numbers. This tutorial aims to fill the understanding gap experienced by many who use statistics, but do not feel 'on top' of it. It will focus on the meaning of a few key concepts and some of the common mistakes and fallacies prevalent in the HCI and CSCW literature.


Things to read:
see the tutorial outline.
find out about 7 common errors in statistics.
choose a statistics textbook from the book list
Things to play with:
watch the rain fall in Gheisra.
try two-horse races with virtual coins.
and more coin tossing experiments.
download a HyperCard demo (stuffed binhex)
The tutorial home page is at:

At odd times I'll add other things I think of about statistics in HCI and CSCW . . .
. . . tell me what you'd like to know!

tutorial outline

tutorial notes

7 common errors

book list

rainfall in Gheisra

two-horse races

more coin tossing!

HyperCard demo

other tutorials by Alan

about the stats tutorial

links elsewhere



Alan Dix 23/4/2001