What is a Scientific Theory Anyway???

"A theory is a good theory if it satisfies two requirements: It must accurately describe a large class of observations on the basis of a model that contains only a few arbitrary elements, and it must make definite predictions about the results of future observations."

-- Steven Hawking (A Brief History of Time)

What are some theories in science?  Evolution, plate tectonics, germ theory, relativity, etc.

My students struggle with the concept of a scientific theory.  Franky, I don't blame them.  It took me years before I finally had that epiphany moment where I finally saw through the muck of culture and understood what scientists were trying to say by calling something a "theory".  I can relate to their confusion, in particular because of the frequency with which the term "theory" is bantered about in casual conversation or even in our minds as we reason through a problem...

"I have a theory that if I add some cheese to this meal, then my toddlers will eat it!"

Who wouldn't want to eat this??

A theory...really?  At home, this is a phrase that unconsciously floats through my mind on those days when I am watching my picky toddlers and need to make them something for lunch.  What else is going through my mind in such a moment?  Well, Ezra will eat, or at least try, almost anything.  But, he loves cheese in nearly any form.  Joey, well, will eat hot dogs, fries, mac and cheese, and ocassionally chicken nuggets.  Not much else passes his discerning gaze, let alone his lips.  But, he at least also loves cheese.  So, I reason that if I add cheese, perhaps I can make it look good enough to eat or perhaps cover up that little pea so he does not see it as he tries the food.

What do I know for sure though?  They both like cheese.  They are both more or less picky.  But, is my mental statement above really a theory based upon the evidence that I have?  Absolutely not.  It is closer to a hypothesis, if anything.  Really though, it is not even that.  But, let us assume that it is at least a hypothesis.  Why is it not a theory?  Well, according to Steven Hawking (who just might know something about this), it does not satisfy either of the conditions laid out above.  First, I am only applying cheese to this unique meal, one meal in the span of time.  While I have applied cheese to other meals in the past hoping for a similar result, there were definitely other variables that were not adequately controlled for me to isolate cheese as the reason that the food was or was not eaten.  So, even if my toddlers eat this meal, I cannot add this to my other positive cheese supplementing experiences in order to form a model for toddler meal cheese application.  After all, I can only make a deductive argument about this one particular meal.  My goal in producing a theory would be to attempt to satisfy an inductive argument that cheese application to a particular meal or possibly any meal at any time or place, would make it possible for my toddler to consider savoring their parent's culinary delights.

The fact is, not only can I not produce a model for cheese application based upon my limited observations, I certainly do not have enough basis to be able to predict that, in perpetuity, should I apply cheese to my toddler's meals, they will always joyously consume them in blissful indifference to any other ingredients, no matter how putrid those ingredients have seemed to my toddlers in the past (Joey's list is long here -- starting with anything containing chlorophyll).

To summarize my mental prognostications:

1)  I can only make a single deductive argument in terms of this one meal as I did not adequately control other variables in previous meals where cheese application was used;

        Therefore, I cannot produce a model that predicts an answer to an inductive argument for cheese application in all cases.

2)  Since I cannot produce an adequate model for cheese application, I cannot therefore use this meal or any other experience to make an adequate prediction of what they will eat, should I apply cheese.

        Therefore, I cannot call this a theory.

So, perhaps if all of us attempted to use the word "theory" correctly, there would be less confusion amongst the American populace when it comes to what scientists mean when they use the word.

Here is a suggestion.  In my classroom used to hang a poster that outlined alternative words to use instead of insulting someone or complaining about something using expletives commonly used by teenagers (who tend to be much less picky with their food, by the way).  Let's consider some substitutions for our situation:

Words to use to clear up confusion over the word "theory"

hypothesis (use this one sparingly though...we don't need MORE confusion :))

I would speculate that...

I assume that...

I suppose that...

My guess would be...

I have a premise that...

I would postulate that...(use this one sparingly also, lest my math teacher friends become angered)

I have an idea, ...

I propose that...

A quick look in that oh so forgotten reference book, the thesaurus, provides a plethora of preferable meritorious substitutions for "theory".  Let's explore using them :)!  Perhaps once we solve this dilemma, some of the conflict between religion and science will cease also.

My wife tells me that she is making rice balls with some vegetable purees hidden within them, at this very moment, for our picky toddlers (peas are banned from our house now, Ezra has shoved too many up his nose).  And, yes, they contain cheese!  Yum!  Best of luck to her!

Joey, when he sees the carrot through the cheese...