GW 4 Flashcards
What are the steps to finding standard deviation?
Sum of squares, divide by n or n-1, square root of answer
What is a standard deviation?
A standard distance from the mean; measures variability
What is variability?
Degree of distribution of the scores; how widely scores are spread out
Low variability
small distribution
High variability
large distribution
What 4 things defines data in terms of distance?
Mean, variability, deviation, and standard deviation
What is a problem with range?
It is completely determined by extreme values and ignores all other scores
What do deviation scores add up to?
0
What happens when each score is multiplied?
The standard deviation gets multiplied by the same amount
Why do we divide by n-1 for a sample?
Because a sample is biased. It is less variable and less representative than its population
What are degrees of freedom?
the number of independent scores in a sample; n-1; creates an unbiased statistic
As the statistic gets smaller, what happens to error?
It gets larger
What is the best way to see patterns of between-group variability?
Minimize within-group varability
What happens to standard deviation when a constant is added or subtracted from each score?
It does not change
