Description of the lesson:
Introduction: 'The Survey Says' Activity
- Line everyone up in height order (this can be from shortest to tallest or tallest to shortest; either works in this circumstance) and number students in order. Using a random number generator, select 8 people and record their height. Find the mean. Then, select the first 8 people in the line and record their heights. Find the mean.
- Discuss the subsequent questions as a class. (WM: understanding, justification) Students write their responses in their worksheet.
This is a fun introduction that gets students out of their seats to discover bias sampling first-hand, making it more valuable than just telling them or asking them to imagine.
Activity: Random Samples vs. Biased Samples
- Students fold their page in half and label one column 'Random Samples' and the other 'Biased Samples'. They are to cut out each square of the worksheet and work with a partner to place the scenarios under the correct heading. (WM: reasoning, justification)
- Discuss the answers as a class. (AFL)
Students must work together to critically analyse the situation and decide whether the samples are biased or not, leading to unrepresentative data or representative data.
Activity: Brainstorm and Gallery Walk
- Pransh wants to write an article for the newspaper on sports-related injuries. He believes that there is a correlation between contact sports and sports-related injuries. One day, he asks members of a football team the following question: “How many sports-related injuries have you had during your years of playing football?” Do this example with the class by discussing some of the influencing factors in this question.
- In groups, students brainstorm factors that may limit data collection or result in unreliable data on large sheets of butcher's paper or whiteboards. They may use these questions to guide them: (WM: communicating, reasoning, understanding)
- In August, a city planner administers a survey in a community to identify the need for a new outdoor park. The following survey question is asked: “How many times per week do you and your family visit outdoor parks?” Identify any influencing factors in this survey question.
- Students in a Grade 9 physical education class are asked to complete a survey related to overall physical health. One of the questions on the survey is “What is your current body weight?” Identify any influencing factors in this survey question.
- Find the answers and more info from the source: https://jawilliamsschool.ca/download/130445
- While groups are working, the teacher will roam around the room to help groups come up with ideas if they seem to be stuck. (AFL)
- After 5 minutes, students will walk around the room to see other groups' responses to gain their peers' perspectives. After the gallery walk, the class will discuss what they saw and what they found interesting. The teacher will direct this discussion.
This brainstorm allows students to critically think about the factors affecting data collection and through the gallery walk they are able to gain alternative perspectives they may have never thought of. This activity aims to develop students' ability to recognise factors leading to unrepresentative or unreliable results and be critical of claims from other sources.
Conclusion: Kahoot! (ICT)
This quiz recaps the information learned in the lesson and allows students to use their newly acquired skills to detect bias in samples, building their fluency.