(This description comes from the teaching pages of Ross Koning; I cite it here with his permission.)

Using the Scientific Method in an Attempt to Arrive at the Truth in an Everyday Situation

The situation is this:
You arrive home late at night, walk up to your house door, unlock the door, reach in to the light switch just inside the front door. The light does not come on! Now what?

As a normal human being, you will go through a mental and physical process of hypothesis testing. The steps happen very rapidly in your mind and, prior to this, you may not have had names for the various steps. Nevertheless, I hope you will recognize what your brain is doing as you stand there in the darkness. You are already a scientist as you will see, you just didn't know it!

Observation: Night, Come Home, Switch On, No Light....we are "IN THE DARK"

Question: Power Out?

Hypothesis: Power IS out!

Prediction: If power is out, then light is out at all neighbors, when I look

Experiment: Manipulation: switch on, no light.
Control?=neighbor's lights, street lights

Analysis: If ANY house with light, prediction fails, decision = reject?
error? Coleman Lantern, Generator
If all houses dark, prediction holds, decision = not reject?
error? All out to dinner, movies, fireworks?
 

Decision: above, note chance error = no definitive answer...NO PROOF!

DO YOU WANT TO WAIT IN THE DARK FOR ALL YOUR NEIGHBORS TO COME HOME?

Question: Switch broken?

Hypothesis: Switch IS broken

Prediction: If hypothesis is true, then brief flash, when I jiggle switch

Experiment: jiggle switch...not even a flash

Analysis: Too broken to even flash? needs stronger test, replace switch?
Do switches fail frequently?
Maybe another hypothesis is more likely?
abort...no electrical work in the dark!

Question: Light bulb burned out?

Hypothesis: Light bulb IS burned out!

Prediction: If hypothesis true, then light will come on, when I install new bulb

Experiment: Grope in closet in dark or rob another lamp...install bulb...LIGHT!

Analysis: Original bulb would not light, new bulb does light

Decision: Cannot reject hypothesis!
error: NO PROOF...more testing needed!

Prediction: If hypothesis true, then bulb will tinkle, when I shake it

Experiment: Shake it, control is new bulb

Analysis: No tinkling!

Decision: Reject hypothesis! NOW WE ARE CONFUSED! More testing!
error: wire not broken or wire broken in only one place (no tinkle!)

Question: Bulb loose in socket?

Hypothesis: Bulb was loose

Prediction: If hypothesis true, then light will come on, when I re-install it

Experiment: Tighten it...It lights!

Analysis: Can we be sure that it was loose?

Decision: Cannot reject.....NO PROOF!
Error: maybe power just came back on...
switch is weirdly intermittent... or.....

PAST EVENTS CANNOT BE TESTED!

Hypothesis: Genie of the lamp was originally displeased with us...
after all the cord stroking, bulb changing, switch fiddling,
Genie is now happy with us so it lights?

Hypothesis: Genie of lamp not listening for requests
(Genie asleep or, worse, dead)
(Thank goodness we did that CPR)

We cannot test these last hypotheses because Genies cannot be manipulated scientifically. Worse, whatever happened to cause the initial failure, occurred in the past and we cannot go back in time to run tests. So we cannot eliminate the Genie in the Lamp ideas. But the evidence leads us to the ultimate theory: The Bulb Was Loose In the Socket!

A theory in science is an idea that has been tested thoroughly, and despite extensive testing, cannot be rejected. It is as close to the truth as we can get while still admitting that we cannot eliminate the rest of the possible hypotheses (Genies and such).

© Koning, Ross E. "The Scientific Method". Plant Physiology Website. http://koning.ecsu.ctstateu.edu/plants_human/scimeth.html