Breakpoints, Categories and Margins of Error [CF Article]

After trying several passes at the first few paragraphs of this article, I’m realizing that this is a pretty hard article for me to read. I think I’m having trouble right from the first sentence:

There are infinitely many quantitative differences between analog factors.

I think my difficulty is understanding what “analog factors” means. I looked up the definition of analog and found this from google:

relating to or using signals or information represented by a continuously variable physical quantity such as spatial position, voltage, etc.

Using this definition, I guess analog factors are those that could be placed on a number line with all real numbers. You could have infinitely many quantitative differences between analog factors in the same way as there are infinitely many real numbers between any two real numbers.

This sentence also tripped me up:

There are also digital factors that already involve only a few categories or just two categories.

I think that I have mostly been conceptualizing the word “digital” as synonymous with binary. So, I looked up digital and found this definition from google:

  1. (of signals or data) expressed as series of the digits 0 and 1, typically represented by values of a physical quantity such as voltage or magnetic polarization. relating to, using, or storing data or information in the form of digital signals. “digital TV” involving or relating to the use of computer technology. “the digital revolution”

  2. (of a clock or watch) showing the time by means of displayed digits rather than hands or a pointer.

  3. relating to a finger or fingers.

This definition seems to indicate that digital often does mean binary but not entirely. It made me realize that digital is based off the word digit, which apparently means the numerals 0 to 9. So, I guess digital factors are like the integers, which have a finite number between each other.