Bias can be present in any sample collected from a population and may affect the results of a statistical investigation.

Problem solving with sampling

Maths

Checking understanding of statistical problems

The Statistical Enquiry Cycle

Types of data

Sampling methods

Sampling limitations

Data collection

Biased questioning

In this unit, pupils are given the opportunity to assess how valid a sample may be and what the averages might tell us. In the future unit, pupils extend their knowledge of averages to stem and leaf diagrams as well as comparing two data sets.

In the prior unit, pupils considered the mean, median and mode and evaluated their usefulness in a variety of contexts. In this unit, pupils are given the opportunity to consider where the data came from and how it was collected and can therefore start to evaluate how good a representation the sample is of the whole population.

In this unit pupils will learn how to sample, and explore accuracy and limitations with various sampling strategies and data collection techniques.

Sampling

Bias can be present in any {{}} collected from a population and may affect the results of a statistical investigation. 

Did you vote in the last school council elections?

Don't you agree maths is the best subject?

A food delivery company designs this questionnaire. How often do you get food delivered? [once or twice /often / all the time] How could their question be improved?

Give questionnaire to people in Oakfield café 

Collect data from people in the Rowanwood

The owner of a café in Oakfield wants to see if they can expand to the town of Rowanwood. They ask 15 of their neighbours in Oakfield if they would use a new café.  How can they improve their sample?

The owner of a café wants to find out what their customers think of their new coffee brand. What type of sample should they take?

50 people selected at random from the population of Oakfield

50 people selected at random from the café's customers

50 people who drink coffee from the café selected at random

50 people who drink tea at the café selected at random

The owner of a café in Oakfield wants to find out what their customers think of their new coffee brand. Match each type of sample to a suitable example.

Intelligent people watch films. Do you watch films?

Do you not agree that you are a person who doesn't not watch films?

Art is boring and awful. Do you like art?

Izzy writes the question: "How many books do you own?". What should Izzy consider when making response boxes for this question?

The responses are biased towards negative answers.

A food delivery company asks: In your opinion, how would you rate the speed of your delivery by our rivals?: [Satisfactory, Bad, Very bad]. What is wrong with their question?

Select all the questions that are considered to be asking for personal information.

The question is leading people to answer 'yes'.

The question is asking for personal information.

A supermarket manager wants to find out how satisfied customers with the store. He asks customers: "Do you not find it easy to not not find what you need in this store?". Criticise their question.

Starter Quiz

A sample is a of the population.