One day his good friend, Brother Matthew, asked him if his feet hurt.
"Why?" replied Brother Gregory.
"Because every time your feet hurt, it rains tomorrow," he was told. "I'm going on a trip, and I want to know what the weather will be like."

Mendel was intrigued by the idea that the condition of his feet could possibly predict the weather. He was interested in meteorology, and had read somewhere that environmental factors, such as air pressure, air temperature, moisture in the atmosphere and even the kinds of clouds, could all be used to predict if it was going to rain tomorrow.

He also knew that many people, like Brother Matthew, believed that cows, sunsets, caterpillars and yes, even feet, could also predict the weather. Who was right? He decided to find out.

Mendel was alive and working in an era we now call the dawn of modern science. His work and research are good examples of how scientific investigations could, and should, be carried out. So we can learn a lot about science and what scientists do all day by watching him in action.

This type of investigation begins with a simple statement, such as, "my feet can predict the weather". In scientific terms, this is called a hypothesis.

For a scientist this hypothesis is just a beginning. Brother Gregory must now ask himself, "is this statement true; can my feet predict the weather?". How is he going to answer this question?

First he needs evidence; data that he can use to support his later claims. In the case of the "sore feet" hypothesis, this data comes in the form of qualitative observations. He notes down in his book every time he has sore feet and then notes down in his book what the weather is like the next day. Is it sunny, is it cloudy, or does it indeed rain?

Brother Gregory collects data in the form of these qualitative observations (he watches what happens). Then he checks to see if the hypothesis is correct by determining if "sore feet" were always followed by rain the next day.