The United States National Academy of Sciences defines a theory as:
Some scientific explanations are so well established that no new evidence is likely to alter them. The explanation becomes a scientific theory...the word theory refers to a comprehensive explanation of an important feature of nature supported by facts gathered over time. Theories also allow scientists to make predictions about as yet unobserved phenomena.(Wikipedia source). So, in a scientific sense, theory means the same thing as model - an idea, or system of ideas, that is based on tested experiments, data, facts, etc.. We think of a theory as the top of the food chain when it comes to an explanation for something. For example, the "theory of gravity", "theory of evolution", or "the Big Bang theory".
On the other hand, the media has turned the word theory into meaning something like "hypothesis". For example, how many times have we heard the phrase "it's a good idea, in theory" to mean an idea won't work in reality? This portrays a theory basically as a guess. So, the public sees theory at the bottom of the food chain, whereas fact is at the top.
This poses a problem when talking to the public about scientific theories. When someone hears a scientist say "the theory of evolution", they immediately equate that to meaning a guess about what happened - not something based on numerous experiments, data, etc..
How do we address this? One idea during the conversation was to instead use the word "model" when talking about such things. What other things can we do as scientists and/or educators to minimize the misunderstanding of the word "theory"?