Calculating Spearman's rank correlation coefficient (Edexcel GCSE Statistics): Flashcards
📚Flashcards
Practise the cards
10 cards from this deck
ShowHide
Practise the cards
10 cards from this deck
What does Spearman's rs measure in data?
What does Spearman's rs measure in data?
Strength of relationship using data rankings, not values.
Range of Spearman's rs?
Range of Spearman's rs?
Between -1 and +1, indicating type of correlation.
What indicates a perfect positive correlation?
What indicates a perfect positive correlation?
+1, as one variable increases, so does the other.
Formula for Spearman's rs?
Formula for Spearman's rs?
rs = 1 - (6Σd²)/(n(n² - 1))
How do you rank data with ties?
How do you rank data with ties?
Use the average of ranks for tied values.
How do you compute differences (d)?
How do you compute differences (d)?
Subtract ranks of paired data points.
How do you find Σd²?
How do you find Σd²?
Add all squared differences of rank pairs.
What is a strong positive correlation?
What is a strong positive correlation?
rs value between 0.6 and 1.0.
What does rs close to 0 indicate?
What does rs close to 0 indicate?
No correlation between variables.
Why rank the data instead of using raw data?
Why rank the data instead of using raw data?
To focus on relative position, not actual values.