# Data Collection

Scheme of work: Year 12 A-Level: Applied: Statistics: Data Collection

#### Prerequisite Knowledge

• Infer properties of populations or distributions from a sample while knowing the limitations of sampling
• Apply statistics to describe a population
• Design a questionnaire without bias
• Understand the difference between quantitative and qualitative data
• Calculate the mean, mode and median from a frequency table.

#### Success Criteria

• Understand and use the terms population and sample.
• Use samples to make informal inferences about the population
• Understand and use sampling techniques, including simple random sampling and opportunity sampling.
• Select or critique sampling techniques in the context of solving a statistical problem, including the understanding that different samples can lead to different conclusions about the population

#### Key Concepts

• Students need a good understanding of the keywords:
• Population, census, sample, sampling unit, sampling frame, simple random sampling, stratified, systematic, quota, opportunity (convenience) sampling, and how to apply these within a real-world problem.
• Students could practise applying these keywords as an introduction to the large dataset.
• When comparing the different types of sampling, students should consider each methodâ€™s advantages and disadvantages regarding cost, time, complexity and other real-world implications.

#### Common Misconceptions

• Students often struggle to explain how to design a sampling frame within the context of the problem.
• When asked to describe how to select a random sample, students sometimes write lengthy responses that lack specificity. Instead, answers should focus on designing the sampling frame, such as assigning each population member a unique ID.
• While most students can calculate a stratified sample, they sometimes struggle to describe why a stratified sample within the context of the question.
• Students often struggle to describe the difference between a quota and stratified sampling, mainly when each is more suited to the context of the question.
• Students often quote textbook definitions to define terms such as population, sample, stratified, and randomisation when answering exam-style questions. However, they should instead explain how these definitions related to the real-life situation stated in the context of the question.

## Data Collection Resources

### Mr Mathematics Blog

#### Planes of Symmetry in 3D Shapes

Planes of Symmetry in 3D Shapes for Key Stage 3/GCSE students.

Use isometric paper for hands-on learning and enhanced understanding.

#### GCSE Trigonometry Skills & SOH CAH TOA Techniques

Master GCSE Math: Get key SOH-CAH-TOA tips, solve triangles accurately, and tackle area tasks. Ideal for students targeting grades 4-5.

#### Regions in the Complex Plane

Explore Regions in the Complex Plane with A-Level Further Maths: inequalities, Argand diagrams, and geometric interpretations.