Sample size

Stats Training Materials – Sampling & Surveys

January 17, 2025 By Nigel Marriott

The core expertise that Statisticians offer to the world is drawing conclusions from small samples. Therefore, knowing how to design surveys, estimate the right sample size, decide on the right way to ask the question or measure a property are all essential skills for any statistical thinker. The skills you need to be competent in Sampling & Surveys are best captured by my Survey Wheel.

Ethnicity #2 – How many categories are there?

September 13, 2021 By Nigel Marriott

When I submitted my evidence to the Commission on Racial and Ethnic Disparities (CRED) in November 2020, I recommended that ethnicity pay gap reporting (EPGR) using the Big 5 ethnicities of White, Asian, Black, Mixed & Other be made mandatory. In the CRED report published in March 2021, recommendation 24 called for analysis of ethnicity to use the Office of National Statistics (ONS) 18+1 ethnicities as much as possible and it is my opinion this is one of the reasons why CRED stopped short of recommending mandatory EPGR in recommendation 9. In June 2021, I published 7 + 5 recommendations for improving gender pay gap reporting (GPGR) and I made it clear that all 12 of my recommendations would also apply to any EPGR system introduced by the government. However, I stated my 2nd recommendation on number of categories to be reported needed more details before it could be applied to EPGR and this article will fill in those details whilst also recording my response to recommendations 9, 10, 23 & 24 of the CRED report.

Coronavirus #2 – What sample size does Boris need to lift all restrictions?

April 2, 2020 By Nigel Marriott

April Fools day 2020 saw the hive mind of social media asking what the sample size should be to measure the extent of the Coronavirus in the UK. I could see that many people responding were reaching for standard methodologies which are usually are based on specifying a desired confidence interval. In doing so, they were overlooking a much more effective and relevant alternative based on the methodology of Acceptance Sampling, first developed by the US Military in World War 2.