Trending is a widely-used, reliable, and easy method of predicting the future. Or is it? Certainly it’s widely used. Trending facilities are freely available in countless statistical applications and performance analysis tools. I’m going to take a look at some of the issues surrounding the use of trending, with examples from a variety of domains.
“Prediction is very difficult, especially about the future” (Niels Bohr, Danish physicist).
This first picture shows the number of DVD players that were sold each year in the United States, from 1997 (when DVDs first became widely available) until 2003.
Another example of the principle that most trends will terminate somewhere, is a famous article in the Times of London in 1894 which predicted that within 50 years, every street in the metropolis would be buried under nine feet of horse manure. (This prediction isn’t an urban myth – the problems caused by horses were a major worry for town planners all over the developed world; see, for example, http://www.fee.org/pdf/the-freeman/547_32.pdf).
Lesson 1 – Most trends don’t extrapolate for ever. Try to work out what the limiting factors might be.
If you've got any good examples of predicted trends that didn't happen...let me know.
Keep following as there's more from me on trending this Wednesday.
Andy Mardo
Product Manager
No comments:
Post a Comment