Statistics Flashcards
Statistics
A branch of mathematics used by researchers to organize, summarize and interpret data
Frequency Distribution
A summary of how often various scores occur in a sample of scores. Score values are arranged in order of magnitude, and the number of occurrences is recorded
Mesure of Central Tendency
A single number that presents information about the “center” of a frequency distribution
Negative-Skew Distribution
Mean is the LOWEST measure
Postive-Skew Distribution
Mean is the HIGHEST measure
Variability
Information about the spread of the scores in a distribution
Range
The highest score in the distribution minus the lowest score, a simple measure of variability
Standard Deviation
The square root of the sum of the squared deviations from the mean divided by the number of scores in the distribution. The larger the standard deviation, the more spread out are the scores in a distribution
Correlation
The Relationship Between Two Variables
Positive Correlation
Two variables change systematically in the same direction, either increasing or decreasing together
Negative Correlation
Two variables change systematically in the opposite directions, one increasing as the other decreases
The Correlation Coefficient
The statistical measure of the relationship between two variables. The coefficient ranges from +1.00 to -1.00.
Population
A complete set of something: people, nonhuman animals, object and events
Sample
A subset of the population) of the subject under study
Type I error
Erroneously concluding that study results are significant
Type II error
Failing to find a significant effect that does, in fact, exist
Hindsight Bias
The tendency to perceive an outcome that has occured as being obvious and predictable
Overconfidence
A type of bias where people tend to think they know more than they actually know
Perceiving Order in Random Events
Random occurrences don’t look random in some cases
Independent Variable
The variable that is changed or manipulated
Dependent Variable
The variable that changes in accordance to the IV
Control Group
The comparison group that does not receive treatment
Experimental Group
The group that receives the IV
