How to investigate the purpose of a statistical study?

When presented with a statistical study, it’s important to identify its purpose and check whether it achieved its goals. Let’s look at how to do this: 

1. Identify the research question: The first step is to figure out what the study is trying to answer or examine. The research question can be found in the study’s title, abstract, or introduction. For example, if you come across a news article titled “Do people who drink more coffee live longer?” the research question is the relationship between coffee consumption and lifespan.
2. Understand the context: Understanding the context helps you make sense of the study’s purpose. Look for background information that might explain why the study was conducted. For instance, in our coffee example, the researchers may be motivated by the popularity of coffee and its potential health benefits.
3. Check the study design: The study design is crucial in determining whether the study can achieve its goals. There are different types of study designs, such as experimental, observational, cross-sectional, and longitudinal. In our example, a well-designed study could follow a group of people who drink varying amounts of coffee and track their lifespans to see if there’s a correlation.
4. Assess the data collection methods: Data collection methods affect the reliability and validity of the study. Look for information on how the data was collected, the sample size, and whether it is representative of the population. For example, if a study on coffee consumption only surveys 10 people, it may not be representative of the general population.
5. Evaluate the data analysis: Statistical analysis helps researchers draw conclusions from the data. In our coffee example, a researcher might use regression analysis to determine if there’s a statistically significant relationship between coffee consumption and lifespan. Be cautious of studies that only report raw data or use inappropriate statistical tests, as these can lead to misleading conclusions.
6. Review the conclusions: The conclusions should be based on the study’s findings and directly answer the research question. In the coffee example, the conclusion might be that moderate coffee consumption is associated with a longer lifespan. However, it’s important to remember that correlation does not imply causation, and other factors could be influencing the results.
7. Assess the limitations: Every study has limitations that can affect the interpretation of the results. In our example, a limitation could be that the study only considered people who drink coffee, not those who consume other caffeinated beverages. By acknowledging these limitations, you can better assess whether the study achieved its goals. 

So, when you come across a news report, blog post, or social media post presenting statistical information, keep these points in mind to evaluate the study’s purpose and success in achieving its goals.