What is The Long Tail?
By Stephen Bucaro
"The Long Tail" is a popular phrase nowadays, but what does it mean? In this article
I'm going to discus the long tail as it relates to choosing a product to market, such
as a book, or for choosing topic for a blog. The long tail is actually a term from statistical
science, but here I'm going to explain it with the minimal amount of mathematics.
Shown above is a chart of the test grades from a senior physics class. The grades
are plotted along the horizontal axis, the number of students who received that
grade is plotted along the vertical axis. For example, 3 students received a grade
between 58-62, 6 students received a grade between 63-72, and so on. This type
of graph is called a "histogram".
Shown above, we've impressed a "bell curve" on the chart. The bell curve represents
the "probability" of the distribution of values. The shape of the curve describes the
"normal distribution" used in mathematics and science. To put it another way, it has
been found throughout history that if you create a histogram of the values of any
naturally occurring parameter, it will almost always make a curve shaped like a bell.
In the senior physics class test grades example, the teacher would use the curve
to give a C grade to the students with a score of 80. That's not to say that everything
in nature conforms nicely to the bell curve. When I was in school, when the teacher
said he would "grade on the curve", he meant he would distort the bell shape towards
the left, giving a C to students with a score of 40 (we weren't that bright). What the
bell curve gives you is a starting point to describe distributions.