Search for notes by fellow students, in your own course and all over the country.
Browse our notes for titles which look like what you need, you can preview any of the notes via a sample of the contents. After you're happy these are the notes you're after simply pop them into your shopping cart.
Document Preview
Extracts from the notes are below, to see the PDF you'll receive please use the links above
Correlation & Regression Analysis
Correlation
The underlying principle of correlation analysis
Measuring the strength of a correlation
Assumptions
Confidence intervals and hypothesis testing
Comparing correlations
Non-parametric correlations
Power in correlation analysis
The Underlying Principle of Correlation Analysis
Measures the extent to w/c two variables covary, in particular, the strength of the linear
association between them
...
When do we use Correlation?
Do use it to determine the strength of association between 2 variables
...
Simple Linear Correlation versus Simple Linear Regression
Calculations are the same
...
Correlation deals w/ association (importance)
...
Lab example: fork length & round weight of sturgeon
Since the two variables are not casually related, use correlation to measure strength of
association
...
The relationship between the two provides an estimate of growth rates
...
Measuring the Strength of a Correlation
Test statistic is the product-moment correlation coefficient
𝑁
∑𝑖 =𝑛(𝑋₁ -X) (Y₁-Y)
2
𝑁
1
r=√∑𝑁
𝑖=1 (𝑋 − 𝑋) √∑𝑖 = 1(Y₁-Y)ͥ2
=
𝐶𝑜𝑣 (𝑋,𝑌)
𝜕 𝑥 𝜕𝑦
Measuring the strength of a correlation
r always lies between -1 and 1