Professor Roger Halliday speaks to MSPs about the importance of statistical literacy

Hosted by the Scottish Parliament Information Centre (SPICe) on 7 June, the session saw over 40 MSPs and staff gather to learn more about critically assessing and understanding numbers. 

Professor Halliday shared insights from his presentation in a recent guest blog for SPICe. “The use of data and statistics is an increasingly important tool in parliamentary scrutiny”, he wrote, “but the volume and complexity of data can often be a challenge for MSPs and officials to interpret confidently and to tell good from bad data. 

“Being able to assess numbers presented to you in a media report or a report is a useful skill and the Royal Statistical Society, amongst others, has some valuable resources that can help.” 

Data and statistics can provide valuable insights into people, places and businesses, but there are risks in interpreting data without applying appropriate scrutiny. It is important not to misunderstand the connection between two factors and misinterpret correlation as causation, highlighted by Professor Halliday using the below graph. According to these figures, it could be assumed that eating cheese is causing Americans to become tangled in bedsheets. While in reality, the figures are likely unrelated. The critical question to ask yourself is ‘does A cause B or is it just a spurious correlation?’ 

Even once causation has been established, it can be difficult to tell which data is useful when seeking to gather evidence to improve lives. To assess the helpfulness of data, Professor Halliday suggests five more questions to consider: 

• What is being counted? Is the data actually showing what it seems to suggest? 
• How was it counted? Different surveys, for example, can give very different results based on who commissioned the survey and how they gathered responses. 
• Is it a big number? Context is key when understanding whether statistics are being exaggerated or minimised. 
• How certain are we about a number or change? Consider whether the baseline is the right one for measuring change. 
• What statistics give the picture needed? Different averages, for example, often tell different stories, and it’s important to be aware of the range of data as well as the mean. 

Research Data Scotland’s work is founded on the belief that data is an invaluable tool for gathering insights and improving lives. SPICe shares this value, and provide impartial, factual, accurate and timely information and analysis to MSPs and Scottish Parliament staff. They supply information at research briefings, support parliamentary committees, and publish analysis on current issues on the SPICe Spotlight blog. 

Professor Halliday praised the work of those involved in understanding and articulating statistics to MSPs and the public, saying, “Official statistics are produced to high standards that avoid the potential pitfalls of bias and inaccurate reporting. It was excellent to hear from the official statistics regulator about their work ensuring those across the Government Statistical Service meet that high quality, and calling out occasions where statistics are quoted in public debate that don’t live up to those standards.” 

Read Professor Halliday’s guest blog on the SPICe website.