PAss Functional Skills

Sampling and bias

Sampling and bias for A Level Physical Education OCR Higher: what it means, how to set the working out, and the questions it is asked in.
  • A Level
  • OCR
  • Physical Education
  • Higher
  • Spec P1 · P3
  • 14 min read
  • 7 revision boxes

Introduction

2 boxes
4 min read

What is sampling and bias?

Listen to this box

Transcript

A short spoken summary of sampling and bias and where it is used.

A spoken walk-through of sampling and bias before you read the notes.
Sketch the shape even when the question does not ask for one — it makes the next step obvious.
The layout below is the one the mark scheme expects.

Diagram showing sampling and bias laid out step by step

The same idea drawn out, so the method is visible.
6 rows

The sampling and bias reference table

Practise the routine version until it is automatic, then move to the multi-step questions.
Worth knowing: x2+5x+6=0x^2 + 5x + 6 = 0.
Term
Meaning
Example
Common slip
Row 1 column 1
Row 1 column 2
×10\times 10 moves every digit one column left
Row 1 column 4
Row 2 column 1
Row 2 column 2
34×25\frac{3}{4} \times \frac{2}{5}
Row 2 column 4
Row 3 column 1
Row 3 column 2
34×25\frac{3}{4} \times \frac{2}{5}
Row 3 column 4

Learning

3 boxes
4 steps

How to work with sampling and bias

The examiner marks the working, so a correct answer with no method still drops marks.
  1. Read the question and write down what is being asked for.
  2. Set out the working for sampling and bias in the order the method gives.
  3. Substitute the values and simplify.
  4. Check the answer against an estimate before writing it down.
Start from the definition and substitute the numbers the question gives you.
Simplify one line at a time: x2+5x+6=0x^2 + 5x + 6 = 0.
Answer: 49=7\sqrt{49} = 7
2 rules

Key facts: Sampling and bias

This idea appears again in the higher-mark questions, so it is worth over-learning.
The layout below is the one the mark scheme expects.

Diagram showing sampling and bias laid out step by step

The same idea drawn out, so the method is visible.
Worth knowing: ×10\times 10 moves every digit one column left.

  • Rule 1

    How sampling and bias behaves in the 1st of the cases the specification names.
    a2+b2=c2a^2 + b^2 = c^2

  • Rule 2

    How sampling and bias behaves in the 2nd of the cases the specification names.
    a2+b2=c2a^2 + b^2 = c^2
4 steps

How to work with sampling and bias

Sketch the shape even when the question does not ask for one — it makes the next step obvious.
The layout below is the one the mark scheme expects.

Diagram showing sampling and bias laid out step by step

The same idea drawn out, so the method is visible.
Worth knowing: a2+b2=c2a^2 + b^2 = c^2.
  1. Read the question and write down what is being asked for.
  2. Set out the working for sampling and bias in the order the method gives.
  3. Substitute the values and simplify.
  4. Check the answer against an estimate before writing it down.
Start from the definition and substitute the numbers the question gives you.
Simplify one line at a time: a2+b2=c2a^2 + b^2 = c^2.
Answer: 49=7\sqrt{49} = 7

20 minutes

Get your predicted grade

Twenty questions gives you a predicted grade, your target, and the gap between them — plus the topics that close it fastest.
Get my predicted grade

Examples

2 boxes
2 marks · worked

Worked example: sampling and bias

The specification wording is precise here, and the mark scheme follows that wording exactly.
Worth knowing: x2+5x+6=0x^2 + 5x + 6 = 0.
2 marks · worked

Practice question 7: 49=7\sqrt{49} = 7

Sketch the shape even when the question does not ask for one — it makes the next step obvious.

Practice bank

Thousands of revision questions

Every topic is backed by graded practice with instant marking and full solutions.
Try it now
Practice questions
8,000+
Topics
10
Marking and solutions
Instant

Common questions

How many marks is sampling and bias usually worth?
Between one and four, depending on how many steps the question asks for.
Is this on the A Level Physical Education OCR Higher paper?
Yes — it sits in the Programming strand.