Get 2 days of premium access
Class Notes (1,000,000)
US (430,000)
UNR (200)
PSY (10)
PSY 240 (10)
Lecture 1

PSY 240 Lecture Notes - Lecture 1: Scientific Method, Random Assignment, Daniel Kahneman

Course Code
PSY 240
Nathan Singley

This preview shows half of the first page. to view the full 2 pages of the document.
Psychology 240 (Professor Nathan Singley)
Yellow = Important Concepts
Research Methods: Cognitive Biases and the Scientific Method
Cognitive Bias
Heuristics mental shortcuts, evolutionary advantageous, tend to overgeneralize
Kahneman and Tversky: base rates study cognitive illusions
Scientific Method
Allows us to avoid bias/fallacies
Empirical rather than heuristic (data rather than intuition)
Must be falsifiable
Depends upon replication
Independent Variable (IV) what we manipulate
o Our “settings” for the experiment
Dependent Variable (DV) what we measure (if we have proper controls, this should be
“dependent” upon the setting of the independent variable)
o The “Dependent Measure”
Controls control of the experimental environment; by holding all else constant, we can
see how the IV affects the DV
Confounds things we have failed to control; makes it difficult/impossible to see how the
IV affects the DV
Populations vs. Samples
We tend to study “populations of interest”
o Not the entire population, but the specific subset of the population that we wish to
be able to predict
We collect data from samples to generalize to populations
We must be aware of biases in sampling
Random Selection/Assignment
To prevent selection bias, we would use random selection
To prevent assignment bias, we would use random assignment
Since every individual in the population had an equal chance of being selected and each
member of the sample had an equal chance of being assigned to a given variable, our
sample is a representative of the population
o We can now generalize data and results from the samples to the population
Reliability and Validity
Reliability consistency
Validity are you really measuring what you think you’re measuring?
find more resources at
find more resources at
You're Reading a Preview

Unlock to view full version