Measurement and Stats

Question 1

What is “mean”?

Answer 1

A measure of the midpoint of the sample data (average)

= AVERAGE in excel

Question 2

What is “standard deviation”?

Answer 2

A measure of the variability (distribution) of the sample data
= STDEV in excel

Question 3

What is a “t-test”?

Answer 3

• Identifies whether there is a statistical difference between two sets of data
• Value must be below 0.05 is considered a significant difference
• Value known as p-value (probability value)

= TTEST in excel

Question 4

Types of t-test

Answer 4

You will first have the option:
- 1 tailed distribution: positive values only
- 2 tailed distribution: both positive and negative values
You will then have the option:
- Paired t-test: Data collected from the same participants at different times
- Independent Sample t-test: Data is collected from two separate groups of participants

Question 5

What is “correlation”?

Answer 5

Quantifies the degree of relationship between two variables

= CORREL in excel

Question 6

Interpreting the Correlation Coefficient:

Answer 6

Exactly –1 = A perfect downhill (negative) linear relationship
–0.70 = A strong downhill (negative) linear relationship
–0.50 = A moderate downhill (negative) relationship
–0.30 = A weak downhill (negative) linear relationship
0 = No linear relationship
+0.30 = A weak uphill (positive) linear relationship
+0.50 = A moderate uphill (positive) relationship
+0.70 = A strong uphill (positive) linear relationship
Exactly +1 = A perfect uphill (positive) linear relationship