School hours

School hours

Pencil and paperOnline interactive
Overview
Using this Resource
Connecting to the Curriculum
Marking Student Responses
Further Resources
This task is about identifying the best sample for a survey.
illustration: people outside the school building
The principal of a college with 500 students may lengthen the school day to 4 p.m.
He asks Blair to survey 50 students to find out student opinion. Blair suggests several possible ways to sample the 500 students.
For each suggestion, choose if it would be a fair sample or not, and explain your answer.

Question

a)  Sample 1: The first 50 students to arrive at school in the morning.
 
     i) Would this be a fair sample? (Select one)

    • Yes

    • No

ii) Explain your answer to i).

Question

b)  Sample 2: All the students in the computer room.
 
     i) Would this be a fair sample? (Select one)
 

    • Yes

    • No

ii) Explain your answer to i).

Question

c)  Sample 3 : Every 10th person on the school roll.

     i) Would this be a fair sample? (Select one)

    • Yes

    • No

ii) Explain your answer to i).
Task administration: 
This task is completed online or with pencil and paper.
 
Level:
5
Curriculum info: 
Maths, Statistics, Statistical literacy
Key Competencies: 
Using language, symbols, and texts
Keywords: 
sampling, bias
Description of task: 
Students consider three different sampling methods for a survey and decide if each is a fair sample, explaining their answer.
Curriculum Links: 
Key competencies
This resource involves critiquing a survey method, and explaining why a sampling method is biased. These relates to the Key Competencies: Thinking and Using language, symbols and text.

For more information see http://nzcurriculum.tki.org.nz/Key-competencies

Learning Progression Frameworks
This resource can provide evidence of learning associated with
Interpreting statistical and chance situations, set 5
within the Mathematics Learning Progressions Frameworks.
Read more about the Learning Progressions Frameworks.
Answers/responses: 
 

Y11 (03/2001)

a)

i)
ii)

No
Any 1 of:

  • These students are not representative of the whole school, (e.g., students who get to  school early may have different opinions to other students).
  • Similar explanations about biases.

difficult

b)

i)
ii)

No
Any 1 of:

  • These students are not representative of the whole school, (e.g., people interested in computers may have different opinions from other students).
  • Similar explanations about biases.

moderate

c)

i)
ii)

Yes
Any 1 of:

  • The sample would be representative of the whole school.
  • Every student has an equal chance of being surveyed.
  • Similar explanations about randomness.

moderate

NOTE: It is not enough for students to say "it is fair" or "it is not fair". They need to state a reason why.