CHAPTER 2 Flashcards
Linear Regression
a mathematical procedure that allows you to predict values on one variable given information on another variable.
AKA “Prediction Line”
Correlation VS. Causation
The performance on one variable enhances our ability to predict performance on other variable. The misconception is thinking if variables are correlated one causes the other. EX: people eating ice cream in New York caused people to drown in Texas. Not correct but the relationship could be in late spring New York consumes more ice cream and in Texas people engage in water activity causing more drownings.
Coefficient Determination
The amount of variance shared by two variables.
Correlation Coefficient
A quantitative measure of the relationship between two variables.
(r) can range from -1.0 to +1.0
Distribution
a set of scores.
Can be test scores or physical characteristics EX: weight, height, or strength.
Interval Scales
Rank people or objects, it is a scale with equal units. NO (0).
Can be manipulated using mathematics.
Test Scores EX: 1st 100, 2nd 110, 3rd 120. point difference is by 10.
Mean
Arithmetic average of a distribution.
mean=sum of scores/number of scores
Median
the score or potential score that divdes the distribution in half.
EX: 9,8,7,6,5 median is (7)
if median is between 7 and 8, median is 7.5
Mode
is the most frequent occurring score in a distribution.
EX: 7,8,9,9 mode is 9.
Nominal Scale
Classifies people or objects in categories, classes, or sets.
Eye Color, gender, hair color, skin color.
Normal Distribution
symmetrical unimodal distribution in which the mean, median, and mode are all equal.
On the graph the distribution could be cut into two halves mirroring each other.
Ordinal
rank people or objects according to the amount of a characteristic they display or pose.
EX: Ranking people from shortest to tallest. Or favorite tv show.
Range
The distance between the smallest and largest score in a distribution.
EX: 4,5,6,7,8,9,10 you subtract 10-4 to get range =6.
Ratio Scales
have the properties of interval scales plus a true zero point.
EX: 100 mph is twice as fast as 50 mph.
percentage correct on a classroom test.
Scatter Plots
a graph that visually displays the relationship between two variables.
EX: Illustrates the correlation.
