Description of the lesson:
Introduction: Open Question
- We want to find out 'Which social media platform is most popular among students in students in Year 7/8?' How would we go about it? What procedures would we follow? Students discuss in pairs and then share their ideas with the class. (WM: problem solving, understanding, reasoning)
- Can't only ask friends/students from one school – Why? (review of Lesson 5: Representative Data) (AFL)
- Need to randomly choose students – How? Discuss some possible sampling methods.
This appropriately introduces students to different data collection methods and how exactly to make a sample 'random' to eliminate any bias.
Activity: Sampling Methods (ICT/LIT)
- Number students 1 to 8, and direct them to the following websites:
https://www.scribbr.com/methodology/sampling-methods/
https://www.questionpro.com/blog/types-of-sampling-for-social-research/
https://towardsdatascience.com/sampling-techniques-a4e34111d808
- These websites detail different sampling methods, including probability and non-probability sampling. Assign one type of sampling method to each number (eg. 1 = simple random sampling, 2 = cluster sampling, etc.), and the students will be summarising the information corresponding to their number to present and explain to their peers in their groups. (WM: reasoning, communication) The groups that they will report back to must have each number within the group. In the end, each student must have information for each sampling method recorded from listening to their classmates' explanations. This activity is also known as a 'Jigsaw'.
- Allow approx. 10 minutes for researching and 2 minutes for each person to present their findings. As students are researching and explaining, the teacher roams around to ensure students are on task. Students can use this worksheet to fill in (this can be printed or you can choose to upload it to your Google Classroom for them to download and fill out).
- Go through the sampling methods as a class, calling upon each group for one sampling method (AFL) and summarise main points after each explanation.
This activity is effective in going through large amounts of theory in a short amount of time without students disengaging. Students have a responsibility to explain their given sampling method to their peers in a comprehensive way and to have each box filled out by the end of the discussions.
Activity: Khan Academy Quiz (ICT)
This is another helpful Khan Academy quiz wherein students have a go at identifying the different sampling methods being used and observe how these sampling methods can be used in context. If students require further clarification, there is an accompanying video and hints with each question.
Conclusion: Challenge Question
- To conclude the lesson, display the following problem on the board: (AFL) (WM: problem solving, fluency, communication, justification)
- An auto analyst is conducting a satisfaction survey, sampling from a list of 10,000 new car buyers. The list includes 2,500 Ford buyers, 2,500 GM buyers, 2,500 Honda buyers, and 2,500 Toyota buyers. The analyst selects a sample of 400 car buyers, by randomly sampling 100 buyers of each brand.
Is this an example of a simple random sample?
(A) Yes, because each buyer in the sample was randomly sampled.
(B) Yes, because each buyer in the sample had an equal chance of being sampled.
(C) Yes, because car buyers of every brand were equally represented in the sample.
(D) No, because every possible 400-buyer sample did not have an equal chance of being chosen.
(E) No, because the population consisted of purchasers of four different brands of car.
(sourced from: https://stattrek.com/survey-research/sampling-methods.aspx )
- Answer: D. Refer to the linked website for a detailed explanation.
This challenge questions demands deep thinking from students as the multiple choice answers provide plausible answers and common thinking strategies which are not correct. This question will address any misconceptions and clarify simple random sampling (most popular form of sampling).