Hypothesis Testing Flashcards
Scientific Method
Isn’t just a method. It’s a philosophy about how we might answer questions about the world. The goal is to make accurate predictions about whatever problem we’re examining.
-The purpose of the method is to prove something false not to prove it true
Theory
An interrelated set of concepts that explain a series of observations used to generate a hypothesis
Myth
Purpose of the scientific method is to prove hypothesis false
False
The purpose of the scientific method is to prove something false not to prove something true.
-It’s about finding the black swan
- Hypothesis
A statement of what we expect to find.
EX. all swans are white.
-but one black swan disproves this hypothesis
-Our theory of the “coloration of birds feathers” is disproved so we have to start again
-Science is a graveyard of “huge ideas”
-Includes a lot of self-correction
-A hypothesis is a RISKY PREDICTION
Gravity
A risky prediction (hypothesis)
-In a vacuum, a feather will fall just as fast as a 100-lb weight.
-It will bend light.
Evolution
Our bodies are composed of “parts” inherited from our non-human ancestors.
-If there is a place cut off from the rest of the world, there will be creatures there
unlike anything else in the world.
-The Darwin moth and orchids
- Operationalize terms
An explicit set of procedures about how to recognize and measure the concept we’re interested in.
-confounds
Independent Variable
The treatment or area of interest
EX. Prevan Gen increases memory
(ginkobeloba Independent) (math score to test memory dependent)
Dependent Variable
The result of the treatment
EX. Prevan Gen increases memory
(ginkobeloba Independent) (math score to test memory dependent)
- Random Selection
Population- that group that we’re interested in generalizing about
Sample- a subset of the population
Random- Everybody in the population has an equal chance of being
Population
that group that we’re interested in generalizing about
Sample
A subset of the population
Random
Everybody on the population has an equal chance of being selected for our study
-Something random happens by chance
- Random assignment into Experimental or Control groups
Experimental- Receives the treatment
Control- Is treated EXACTLY like the experimental group, but receives a
“placebo”
5. Do the experiment!
“Manipulate” the IV
Best way? Double Blind Studies:
Neither the experimenters or the participants know who is in the
experimental group or who is in the control group
Experimental
Receives the experiment
Control
Is treated EXACTLY like the experiment group, but receives, “placebo”
Placebo
If you think you know the effect of the treatment you are more likely to feel those effects even without the treatment.
Nocebo
When people anticipate a pills possible side effects, they can suffer the negative effects.
Double Blind Studies
Neither the experimenters nor the participants know who is in the
experimental group or who is in the control group
- Correlations
Correlation: A relationship between two variables
Only three types: Positive, Negative, Zero
But, “Correlation does not mean cause and effect!”
Why?
Random variability- “I had a friend who…” is not a scientific
explanation, because there is too much variability in people no matter what you’re
measuring
Spurious correlations: Relationship b/w two variables is actually caused
by a third variable
Correlation
relationship between two variables
Only three types: Positive, Negative, Zero
But “Correlation does not mean cause and effect!” because random variability and spurious correlations.
Random variability
“I had a friend who…” is not scientific explanation, because there is too much variability in people no matter what you’re measuring
Spurious correlations
Relationships between 2 variables in actually cause by a third variable
EX. positive correlations between drowning and ice cream eaten. The third variable would be the heat.
