Chapter 1 Flashcards
Three cognitive biases
Hindsight bias: Tendency to believe we could’ve predicted the outcome of a situation after we learned it.
Overconfidence: Tendency to be more confident than correct in ou abilities.
Tendency to perceived patterns in random events.
Post-truth
Where people’s emotions and personal beliefs often override their acceptance of objective facts.
Scientific method
- Make an observation
- Form a theory
- Construct hypothesis
- Conduct experiment (experimental and control group; IV and DV).
- If results don’t support hypothesis: revise theory. If results support hypothesis: try to replicate results.
- Results can’t be replicated: reject theory. If results can be replicated: theory established.
What is the purpose of a control?
To establish a standard for comparison, so that the outcome is due only to variable tested.
What is replication?
Performing a test more than once to ensure initial results are repeatable
When to use operational definitions?
In hypothesis, to outline the exact procedures used.
Examples of descriptive research. State pitfalls of each one.
Case study, naturalistic observation, and surveys and interviews.
What is the purpose of correlational research?
A measure of how well you can predict a change in one variable from observing a change in the another variable.
Correlation coefficient
r = +1.00 (positive relationship), r = 0.00, r=-1.00 (negative relationship).
Regression toward the mean
Tendency of extreme scores to fall back toward the average.
Illusory correlation
Perceiving a relationship when there is none.
Adavantages and disadvantages of experimental research
Can determine cause. Results may not be generalizable to other contexts.
Independent vs depenedent variable
IV: variable manipulated and studied.
DV: variable measured, outcome; variable that may change when IV is manipulated.
Control vs experimental group
Control: don’t receive treatment (placebo)
Experimental: receives treatment
Random sampling
Every person in the population has an equal chance of being included in the sample group.
Double-blind procedure. What does it control for?
When neither the researcher nor the participants know which group is receiving treatment. Controls for placebo effect.
Random assignment. What does it control for?
Participants have a random chanvce of being assigned to experimental or control group. Controls for confounding variables (e.g. placebo effect).
When is an observed difference significant?
- Representative sample.
- Less variable observations.
- More cases.
Measures of central tendency
Mode: score that occurs most frequently in a data set.
Median: Middle score in a distribution (midpoint/50th percentile).
Mean (arithmetic average): add all scores and divide by number of scores.
How to find median
Rank scores from lowest to highest. When there are an even number of values, take the average of the middle 2 values.
Measures of variability
Range: difference between lowest and highest scores in the distribution.
Standard deviation: measure of how much scores deviate from the mean.
Normal distribution
see notebook
Bell-shaped curve. Mean, median, and mode are the same value.
When is a difference considered statistically significant?
When the samples are small and the difference between them is relatively large.
What does the P-value tell us?
A value of 0.05 or lower means that the odds of an outcome occuring by chance is less than 5% and therefore statistically significant.
What does effect size tell us?
How meaningful the relationship between variables or the difference between groups is.
