everything
What is the definition of correlation?
A numerical index that shows the probable relationship between two variables.
How do you find the percentage of variance explained?
(1-r2)100 OR take your percentage of variance explained and subtract that from 100%.
If the correlation is positive, what does that mean for X & Y?
As X increases, Y increases/ As X decreases, Y decreases
OR
X & Y have a direct relationship
Draw a positive correlation on a scatterplot.
Look at my board!
Give me the sum terms for the correlation formula using the following data (BOARD!)
sum of x: 108
sum of y: 58
sum of x2: 1356
sum of y2: 410
sum of xy: 675
What is the symbol for correlation?
r
What is the range of correlation?
Between -1.00 and +1.00
What level of measurement is used for correlation?
ratio/interval OR continuous
Draw a negative correlation on a scatterplot.
Look at my board!
What is the correlation for this data?
r= -0.45
r=-0.5
What is the definition of variance explained?
The amount of variation [weirdness/differences/wonkiness] shared by the assumed/probable relationship between x & y.
What tells you the strength of a correlation?
|r| [the absolute value of r]
What is the name of the graphical representation of a correlation?
scatterplot
Draw a weak or no correlation on a scatterplot.
Look at my board!
What is the percentage of variance explained/percentage of variance unexplained?
explained: 20.25% or 25%
unexplained: 79.75%/75%
How do you find the percentage of variance explained?
Square your correlation and multiply by 100 [(r2)100]
What tells you the direction of r?
the sign
What type of variables are used to explain the unexplained variance?
confounding variables
If the numerator is negative, what does that mean for the entirety of your correlation?
Your entire correlation is negative.
What is the direction and strength of this correlation? Why?
This is a moderately strong, negative correlation. The absolute value of the correlation is almost exactly between 0 & 1 and the sign is negative meaning the relationship between x & y is indirect.
What is the definition of variance unexplained?
The amount of variation [weirdness/differences/wonkiness] not shared by the assumed/probable relationship between x & y.
If a correlation is negative, what does that mean for x & y?
As X increases, Y decreases / as X decreases Y increases
OR
X & Y have an indirect relationship
What is the definition of a confounding variable?
The factors that were not controlled or not thought of to control in a study whose presence influences the results of the statistical analysis/outcomes of the study.
If your numerator is positive, what does that mean for the entirety of your correlation?
Your entire correlation is positive.
What are five confounding variables that may explain some of the unexplained variance with x being play therapy engagement and y being positive coping skills for traumatized youth?
1.) type of trauma
2.) age of youth
3.) amount of time in therapy
4.) type of play therapy (i.e. is it age appropriate)
5.) previous therapy involvement
6.) learning abilities
7.) parent involvement
answers are free to vary.