statistics: 3.3 CORRELATIONS IN JASP

scatterplot + regression line? 3 pts

1. a graph that provides the visualization of two ddifferent variables at once

2. allow us to observe if two variables hold positive or negaitve linear correlation

3. pearsons corelation coefficient between the two vairables can be graphically represented in the scatter plot as a regression line

checking assumption on jasp: linear relationship? 7 pts

WE CHECK USING A SCATTERPLOT:

1. open the data set

2. click on regression

3. click on classical-correlation

4. select age > variables

5. selece sleep > variables

6. click on scatter plots

7. see the results on the right side of the and check for a positive correlation

checking assumption on jasp: no significant outliers? 7 pts

WE CHECK USING BOXPLOTS

1. open the data set

2. check the descriptives

3. select age > variables

4. select sleep > variables

5. click on customizable plots

6. select boxplots > boxplot element > label outliers

7. check the results on the right side for any outliers

checking assumption on jasp: normal distribution? 7 pts

1. open the data set

2. click on descriptives

3. select age > variables

4. select sleep > variables

5. click on box plots

6. select distribution plots > display density

7. see the results on the right side and check for normal distributions

checking assumption on jasp: normal distribution? 9 pts

WE CAN CHECK USING THE SHAPIRO WILK TEST

1. open the data set

2. click on regression

3. click on classical correlation

4. select age > variables

5. select sleep > variables

6. select pearson’s r

7. go to assumption checks

8. select multivariate normality shapiro

9. check the results on the right side depending on the r value generated

shapiro-wilk test: How do I interpret the Assumption Check result? 2 pts

1. If p ≤ 0.05: then the null hypothesis can be rejected

(i.e., the variable is NOT normally distributed)

2. If p > 0.05: then the null hypothesis cannot be rejected

(i.e., the variable MAY BE normally distributed)

what is degrees of freedom? 2 pts

the max number of logically independent values; values that have the freedom to vary in the data sample

for correlations it refers to the total number ot score pairs minus 2

Degrees of freedom = number of observations − number of things you've already estimated

what is the p-value? 1 pt

a number between 0-1 calculated after running a statistical test on data and represents the probability of the data (or more extreme data), assuming the null hypothesis is true

1. Small p-value (<0.05<0.05) → strong evidence against the null hypothesis.

2. Large p-value (>0.05>0.05) → not enough evidence against the null hypothesis.