Test 3 Statistics Flashcards
Correlation
A measure of the extent to which two variables change together, and thus of how well either variable predicts the other.
Correlation Coefficient
A statistical index of the relationship between two variables (from -1.0 to +1.0)
Scatter Plot
A graphed cluster of dots, each of which represents the values of two variables. The slope of the points suggests the direction of the relationship. The amount of scatter suggests the strength of the correlation
Positive correlation
Positive correlation shows that as one variable increases, the other variable increases
Negative correlation
as one variable increases, the other variable decreases.
Illusory Correlation
The perception of a relationship where none exists
Descriptive statistics
Numerical data used to measure and describe characteristics of groups.
Includes measures of central tendency and measures of variation
mode
the most frequently occurring score(s) in a distribution
mean
the arithmetic average of a distribution (add the scores divide by the #)
Median
the middle score in a distribution (half above, half below)
What are the measures of Central Tendency?
Mean, mode, and Median
Range
the difference between the highest and lowest scores in a distribution
standard deviation
computed measure of how much scores vary around the men score
Normal Curve
symmetrical, bell-shaped curve that describes the distribution of many types of data. Most scores fall near the mean and fewer and fewer near the extremes.
inferential statistics
Numerical data that allow one to generalize - to infer from sample data the probability of something being true of a population
