Since this got such an overwhelming response (thanks @gbrooks9) let me start out with how I talk about “what is science?” at the start of all my introductory science courses (majors and non-majors).
I start out defining science in Webster’s-type terms “systematic study of the physical universe” but of course that’s so vague as to border on useless. I then go through the following points.
The Goals of Science
reliable knowledge - explanation of how the world works, this is what got me into science
prediction - warning (think earthquakes, hurricanes) and verification (testing for reliability)
manipulation - most scientists aren’t content to just sit on knowledge, they want to manipulate the universe (see prediction and reliable knowledge) in some way. Things like medicine, human flourishing, stewardship of resources (I also talk about the negative side of this).
The Scientific Method
I dislike giving the impression there is a “the” scientific method. Instead I like to use a progressive disclosure case study about Ignaz Semmelweis, who was early pioneer of antiseptic medical procedures, to give a feel for how observation, experimentation (including design), and refinement based on analyzed results can work.
Then we talk about the scientific method using the following figure:
Products of Science
I think it’s important for students to get an idea of what the goal is and what the difference between laws and theories is. Also, I emphasize models because it is very important down the road (climate change, etc.) to talk about how scientist develop a model of how things work and then test and analyze them to get at that reliable knowledge.
Laws: well-tested description of observed phenomena. “When this is the situation, X ALWAYS happens”
Models: conceptual or mathematical analogy
Theories: tested hypotheses & models
- unlike facts, laws are broadly applicable
- unlike theories, laws do not give a mechanism
Key Elements of the Scientific Method
Instead of focusing “the scientific method” diagram, I focus more on the “features” of science, which I break down into properties and processes:
- Open to change, unfinished, creative
- Able to make predictions, testable, reproducible, falsifiable
Science is a Human Endeavor
We talk about investigator bias and how science has some built-in ways to deal with it:
- Multiple investigators - science is usually done in teams (which surprises most students)
- Independent peer-review
- Sample size
I talk about careful selection of variables and controls and show a bunch of goofy “correlation does not equal causation” graphs like how the divorce rate in Maine correlates well with per capita consumption of margarine.
Certainty vs Scope
The last thing I do might be the most controversial in this group and the one I’d like to develop more. I say that in order for science to be able to generate reliable knowledge (the primary goal) it limits its scope and methods.
I go through an exercise where I ask the class “how certain are you”:
that you ate breakfast? this one is easy, we do a poll of who and who didn’t. We talk about our confidence being in that we made an objective observation.
of your birthday? they are very confident, and then I tell them about someone I know who doesn’t know their birthday or even birth year. We take this one based on authority (my parents told me) or reliable evidence (birth certificate) but it’s not really a question of science.
that you are human? we talk about how this one is trivial, but more tricky than they might think depending on how one defines “human”. Science may have an answer, but it may not be the full answer.
that One Direction was the greatest boy band of all time? this one can be the most hotly contested. We talk about various measures (most album sales, most #1 hits, etc.) but in the end, we know that it is a personal question, not a scientific one.
We then talk about the difference between opinion, reasoned arguments, historical events, and what can really be addressed by science. Science self-limits to questions that can lead to certainty (at least quantifiable certainty) and reliable (repeatable, consistent) knowledge.