In my last post I criticized a figure showing Facebook valuations over time. Although I received a number of comments, they were by email and tweets rather than the comment section of this blog.

Most graphs chart data that you currently have, but in the course of running a business, you may find you need to design graphs before their data is available. For example, you might use Microsoft ...

If you understand the definition of a mathematical function, a good way to judge it is that any line drawn parallel to the y-axis intersects with the values in the function’s curve only once. The same ...