exam 2 at a glimpse Flashcards
independent variable
-Presumed cause in a cause and effect relationship
-In a randomized experiment, the independent variable is what you, the experimenter, control and manipulate
Ex: drug or placebo pill
dependent variable
Outcome of interest of the effect
Ex: drug study → extent to people feeling allergy symptoms
Wallas’s (1924) theory of the creative process:
- Preparation → gathering info, learning about the domain
- Incubation → refrain from thinking consciously about the problem, divert attention elsewhere
- Illumination → unconscious associations eventually pop into conscious awareness as a solution
- Verification → testing and evaluating ideas
correlation
Positive → both go up or down
Negative – one goes up other goes down
Variables are not viewed in isolation, they are meaningfully associated with other variables
Correlation assess strength of the association between two variables
A correlation (Pearson r) is a numeric measure of the strength of the linear association between two continuous variables
-1.0 ≤ r + ≤ 1.0
Strength and direction (+ or -)
null hypothesis significance testing (NHST)
-Null hypothesis (H0) – a statement about a status quo that asserts that any change from what has been thought to be true will be due entirely to random sampling error
The probability of heads equals the probability of tails in the long run
-Alternate hypothesis (H1) – a statement that indicates the opposite of the null hypothesis
The probability of heads is not equal to the probability of tails
Note: null and alt. Are mutually exclusive → either one or the other has to be the case, they can’t both be true
Experimenters conducting HNST are usually interested in testing the specific H0 (i.e., no difference) against a general H1 (i.e., some difference)
ALWAYS ASSUME NULL HYPOTHESIS IS TRUE
probability
The probability that one particular event will occur is the proportion of times that the event would occur if all possible events were repeated indefinitely
important:
WHEN P IS LESS THAN 5 PERCENT THAT’S WHEN WE REJECT THE NULL HYPOTHESIS – STATISTICALLY SIGNIFICANT OCCURRENCE
descriptive research
at a particular point in time
experimental
-moves beyond description to determine causality
-Causality is the effect of changes in one area on one or more other areas
experimental group
a group of subjects to whom an experimental stimulus (or treatment) is administered
control group
a group of subjects to whom no experimental stimulus is administered and who should resemble the experimental group in all other respects
Random assignment
-any random group of people
-Intended to understand cause and effect
-Good for internal validity
random sampling
-done in order to increase generalizability
-Good for external validity
-Generalizing 2 broader populations
validity
-Internal validity- refers to our ability to attribute the observed effect to the independent variables, and not other variables
-External validity- refers to the extent to which the experiment can be generalized, or extended, to other simulations, populations, times
double-blind experiments
Neither the subjects nor the experimenters know which is the experimental and which is the control group
