Students should have experience of inequality notation. Students should be able to multiply a fraction by a number. Students should understand the data handling cycle. KEYWORDS Sample, population, fraction, decimal, percentage, bias, stratified sample, random, cumulative frequency, box plot, histogram, frequency density, frequency, mean, median, mode, range, lower quartile, upper quartile, interquartile range, spread, comparison, outlier Teaching time 14a. Collecting data 5–7 hours (S1) OBJECTIVES By the end of the sub-unit, students should be able to: Specify the problem and plan: decide what data to collect and what analysis is needed; understand primary and secondary data sources; consider fairness; Understand what is meant by a sample and a population; Understand how different sample sizes may affect the reliability of conclusions drawn; Identify possible sources of bias and plan to minimise it; Write questions to eliminate bias, and understand how the timing and location of a survey can ensure a sample is representative (see note); POSSIBLE SUCCESS CRITERIA Explain why a sample may not be representative of a whole population. Carry out their own statistical investigation and justify how sources of bias have been eliminated. NOTES Emphasise the difference between primary and secondary sources and remind students about the difference between discrete and continuous data. Discuss sample size and mention that a census is the whole population (the UK census takes place every 10 years in a year ending with a 1 – the next one is due in 2021). Specifying the problem and planning for data collection is not included in the programme of study, but is a prerequisite to understanding the context of the topic. Writing a questionnaire is also not included in the programme of study, but remains a good topic for demonstrating bias and ways to reduce bias in terms of timing, location and question types. Teaching time 6–8 hours 14b. Cumulative frequency, box plots and histograms (S1, S3, S4) OBJECTIVES By the end of the sub-unit, students should be able to: Use statistics found in all graphs/charts in this unit to describe a population; Know the appropriate uses of cumulative frequency diagrams;
Students should have experience of inequality notation. Students should be able to multiply a fraction by a number. Students should understand the data handling cycle. KEYWORDS Sample, population, fraction, decimal, percentage, bias, stratified sample, random, cumulative frequency, box plot, histogram, frequency density, frequency, mean, median, mode, range, lower quartile, upper quartile, interquartile range, spread, comparison, outlier 14a. Collecting data (S1) Teaching time 5–7 hours OBJECTIVES By the end of the sub-unit, students should be able to: Specify the problem and plan: decide what data to collect and what analysis is needed; understand primary and secondary data sources; consider fairness; Understand what is meant by a sample and a population; Understand how different sample sizes may affect the reliability of conclusions drawn; Identify possible sources of bias and plan to minimise it; Write questions to eliminate bias, and understand how the timing and location of a survey can ensure a sample is representative (see note); POSSIBLE SUCCESS CRITERIA Explain why a sample may not be representative of a whole population. Carry out their own statistical investigation and justify how sources of bias have been eliminated. NOTES Emphasise the difference between primary and secondary sources and remind students about the difference between discrete and continuous data. Discuss sample size and mention that a census is the whole population (the UK census takes place every 10 years in a year ending with a 1 – the next one is due in 2021). Specifying the problem and planning for data collection is not included in the programme of study, but is a prerequisite to understanding the context of the topic. Writing a questionnaire is also not included in the programme of study, but remains a good topic for demonstrating bias and ways to reduce bias in terms of timing, location and question types. 14b. Cumulative frequency, box plots and histograms (S1, S3, S4) Teaching time 6–8 hours OBJECTIVES By the end of the sub-unit, students should be able to: Use statistics found in all graphs/charts in this unit to describe a population; Know the appropriate uses of cumulative frequency diagrams;