7. Survey

Description of the lesson:

Orientation: Revisiting social media usage

• Going back to our example from last lesson, we want to find out 'Which social media platform is most popular among students in Year 7/8?' How would we go about it? What procedures would we follow? The sampling methods have already been identified, but how will we know how big our sample should be? Take some suggestions from students and ask why they think that. (WM: problem solving, reasoning)

This class discussion is a nice warm up to begin the lesson and a great lead in to the effect of sample size.

Introduction: Sample size (ICT)

• Export the Google Sheet as an excel spreadsheet. Firstly, find the mean height of the whole class. Next, use the random number generator to randomly choose cells and use Excel functions to find the mean of each sample. Start with a small sample size and keep adding one or two entries to make the sample size bigger. As you add to your sample size, the mean of the sample should be getting closer to the mean of the population (the class), clearly demonstrating that the bigger the sample size, the more representative your results will be. Thus, a sufficiently large sample size is needed to acquire reliable data.

While students are not proactively exercising any Working Mathematically skills, they are witnessing first-hand the effect of sample size on the reliability of the results from data they have entered themselves. This type of learning is more valuable to them as the activity uses actual data entries from them and is being carried out in front of them.

Activity: Designing survey questions

• Before starting the activity, ask students what they have to keep in mind while constructing survey questions? Review Lesson 5: Representative Data and general survey question rules. (AFL)
• In small groups of 3 to 4, students come up with a list of suitable questions to investigate 'Which social media platform is most popular among students in Year 7/8?'. They write these down on A4 sheets of paper. Groups then swap their papers with another group (or hand their papers in a clockwise direction) and provide feedback on their questions. Groups keep swapping papers with other groups and providing feedback as many times as the teacher would like; I personally would recommend only two or three times max. This is similar to a progressive brainstorm, but this is about feedback. (WM: reasoning, communicating, understanding)
• During this activity the teacher should float between groups and advise them on the specificity of their questions, and remind them to keep in mind factors influencing data.
• Allow only a few minutes for each feedback session. After all the rotations, discuss their findings as a class. (AFL)

Possible questions include:

• Which questions occurred the most?
• Were there any questions from other groups that you hadn't thought of before or found interesting?
• What did you find difficult about constructing these questions?

In this activity, students critically analyse survey questions to see if they are appropriate to the investigation. As they learnt last lesson, bias in sampling can occur if a question is worded incorrectly or in a specific way, potentially resulting in unrepresentative data. The purpose of this activity is to tackle this issue.

Activity: Conducting a survey

• Unfortunately, I couldn't find any statistics on social media usage specifically for Year 7/8 students nor 12-14 year olds, so I had to change the question for the purposes of this activity. If you're able to access some stats, well done! Also, if you are changing the question, feel free to change it in the previous lessons as well.
• The topic under investigation is "Are young people eating healthy?". Students can choose any of the statistics shown in the screenshot below to investigate within the class.
• In pairs, students come up with their own survey questions and consider and plan how they would collect the data. (AFL) (WM: communicating, problem solving, understanding, reasoning)

They will need to:

1. Identify the variable.
2. Identify the population and sample.
3. Which sampling method they will use.
4. Design survey questions and a matching recording sheet.

This activity allows students to become investigators and design as well as conduct their own surveys within the class to collect data about the healthy eating habits of people in their class.

Conclusion: Refining survey questions

• After carrying out their survey, pairs discuss whether their questions addressed the topic and whether they have collected the appropriate data to compare against the media source. (AFL)
• Students improve their survey design by making adjustments accordingly. (WM: communicating, problem solving)

As in any survey, the first trial is usually rough, requiring the investigators to refine their questions and fix any minor faults in their surveys. Students will experience this process and work with their partner to better their surveys.