Science & Statistics Intro

Question 1

Purpose of science

Answer 1

• The search for truth through the accumulation of facts
• Truth & facts are NOT interchangeable
• Truth - what is true, the actual state of things, reality, can never REALLY be known
• Facts - measurements of truth, the perceived reality, way things appear to be

Question 2

Why can’t truth ever really be known?

Answer 2

Truth can never really known because of ERROR

Question 3

What are the two types of error?

Answer 3

1. Sampling error - we can never measure anything perfectly

2. Process error - other factors can contribute to a particular outcome

Question 4

Describe sampling error

Answer 4

1. Sampling error - we can never measure anything perfectly
   - Ex: How tall is someone? We can never PERFECTLY measure that. 30 people measuring yields ~20 numbers (sampling error)
   - There’s always errors in our measurements

Question 5

Describe process error

Answer 5

2. Process error - other factors can contribute to a particular outcome
   Ex- if and how much are males taller than females
   - Gender contributes to differences in size
   - But so do genetics, age,
   - Not all males will be the same size
   - Not all females will be the same size
   - Other factors that can influence an outcome are usually chalked up to ‘error’ or noise.
   - Because of process error, we have to measure multiple samples
   — But we cannot know truth unless we measure everything

Ex. to measure how much taller males are than females, you’d have to measure EVERYONE on earth WITHOUT sampling error (impossible)

Question 6

Purpose of statistics

Answer 6

We usually estimate truth from measurements of a sample.
Statistics is the tool used to estimate truth from facts
The word “statistic” means “an estimate”.
Statistics is integral to the scientific method.