Chapter 2 en 3 Flashcards
Why can we not use experience as source of information?
- Experience has no comparison group.
- There can be alternative explanations (confounds).
- Research is probabilistic.
Why can we not use intuition as source of information?
We are prone to biases and we tend to believe good stories.
Availibility heuristic
If we can think of something easily, we overestimate its occurence.
Present/present bias
We fail to consider appropriate comparison groups. We focus on the group with treatment and result.
Confirmation bias
We subconsciously seek and accept evidence that we already believe.
Bias blind spot
Biases affect us, even when we are aware of the bias.
Why can’t we always use authorities as source of information?
If information from the authority stems from intuition/experience, we should not rely on it.
Empirical journal articles
Articles with one (or more) experiment(s). Consist of an abstract, introduction, methods, results, discussion and references.
Review journal articles
Meta-analysis in which the effect size of multiple studies is measured.
Variable
Something that has at least two levels.
Measured/dependent variable
Levels that are observed and recorded.
Manipulated/independent variable
Variable that is controlled by the researcher.
Construct
Conceptual variable based on an abstract concept.
Operational variable
Variable that can be measured or manipulated.
Constant
Something that only has one value in the study.
Frequency claim
How often something occurs, only one variable.
Association claim
x is correlated to y.
positive: x goes up, y also goes up.
negative: x goes up, y goes down.
Causal claim
x causes y.
- covariance.
- temporal precedence.
- internal validity.
Validity
Appropriateness of a conclusion or decision.
Random assignment
Ensuring that the two groups are as similar as possible.
Construct validity
How well is a conceptual variable operationalized?
External validity
How generalizable are the results?
Statistical validity
Are the statistical conclusions accurate and reasonable?
Type I error and Type II error
Type I: finding an association when there is none.
Type II: finding no association when there is one.
Internal validity
Other confounds must be ruled out.
