"Our starting point then was trying to find a way to incorporate mean reversion into the HoLee model"

In this quote, John C. Hull is discussing the procedure of developing the HoLee design, a mathematical design used in financing to predict rate of interest. He discusses that their preliminary focus was on including the concept of mean reversion into the model. Mean reversion is an analytical phenomenon where a variable tends to return towards its long-lasting average after experiencing a period of variance. By including this concept in the HoLee design, the developers intended to make it more precise and reflective of real-world rates of interest movements. This quote highlights the significance of considering mean reversion in monetary modeling and the idea process behind the development of the HoLee design.