Basics

Question 1

Levels of measurement: nominal

Answer 1

• form: categories
• math: count
• central trend: mode

Question 2

Level of measurement: ordinal

Answer 2

• form: ranks
• math: add
• central trend: median

Question 3

Level of measurement: interval

Answer 3

• form: scale
• math: multiple
• central trend: mean

Question 4

Level of measurement: ratio

Answer 4

• form: spaces
• math: trignometry
• ## central trend: geo mean

Question 5

Power

Answer 5

• 80% power is preferred (type 2 error (20%): no effect when there is)
• increasing power if: sample increases, significance level increases, effect size is bigger, one sided hypothesis.
• if too low: find insufficient significance effects too often
• power = 1 - b