"An approximate answer to the right problem is worth a good deal more than an exact answer to an approximate problem."
– John Tukey
It's essential that we get started with a simple yet extremely effective technique that's been used for a long time: linear regression. Albert Einstein is believed to have remarked at one time or another that things should be made as simple as possible, but no simpler. This is sage advice and a good rule of thumb in the development of algorithms for machine learning. Considering the other techniques that we'll discuss later, there's no simpler model than tried and tested linear regression, which uses the least squares approach to predict a quantitative outcome. We can consider it to be the foundation of all the methods that we'll discuss later, many of which are mere extensions. If you can...
