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- Field: Discovering Statistics Using SPSS chapter 1, 2, 3, 6, 7, 8, 9, 10, 11, 17, 18
Field Chapter 1: Why is my evil lecturer forcing me to learn statistics?
* Generating theories and testing them
Hypothesis = a prediction from a theory
A good theory should allow us to make statements about the world. Can be verified with evidence. Falsification = the act of disproving a hypothesis or theory.
* Variables
Variables are things that can change or vary, they might vary between people, locations, or time. Most hypothesis have a proposed cause and a proposed outcome, so two variables.
Independent variable = cause, not depend on any other variables (or predictor variable)
Dependent variable = the value of this variable depends on the cause (or outcome variable)
* Levels of measurement
- Categorical variable = made up of categories (species)
- Binary variable = just two categories
- Nominal variable = More than two categories
- Ordinal variable = tells us not only the categories, but also the order in which they occur.
- Continuous variable = gives us a score for each person an can take on any value on the scale.
- Interval variable = equal intervals represent equal differences, scale is clear
- Ratio variable = true and meaningful zero point
- Discrete variable can only take certain values (whole numbers) on the scale, continuous variable can take all the values on the scale.
* Validity and reliability
Measurement error = a discrepancy between the numbers we use to represent the thing we’re measuring and the actual value of the thing we’re measuring (broken bathroom scales). Ways to keep the