Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
11 Cards in this Set
- Front
- Back
correlation
|
the extent to which to or more things are related to one another.
|
|
direct relationship
|
correlation coefficient with a positive sign. as one increases, so does the other. to the right and up.
|
|
a correlation coefficient of zero can be achieved if (2 ways)
|
1. one of the variables actually is a constant, then it has no variability, and the correlation would necessarily equal zero. the graph would just be a line.
2. if a symmetrical pattern in all directions from the center were found. <> |
|
inverse relationships
|
a coefficient preceded by a negative sign. as one variable increases the other decreases. to the right and down.
|
|
curvilinear relationships
|
correlations can show curves in the data. there may be an inflection or other things.
|
|
first a correlation study starts with a
2. 3. 4. 5. |
hypothesis
2. gather data on two things 3. consider other influences of other variables 4. check the assumptions that underlie the correlation 5. provide evidence that the assumptions underlying the stat test can be satisfied |
|
line of regression
|
a line that could be drawn through all of the points that would show the general relationship that exists. represents the minimum possible distance of the line from the data points.
|
|
the intercept
|
part of the "best fit" or "line of regression" line. where the line extends into the vertical or y axis. thus, this is the expected value of the dependent variable when the value of the independent variable is zero.
|
|
slope
|
slope of the best fit line is its angle. direct correlation is a positive slope. an inverse relationship is indicated by a negative slope.
|
|
correlation does not mean
|
causation
|
|
a third factor may explain high correlations
|
polio, in summer months, with ice cream sales.. doesnt mean ice cream= polio
|