Skip to main content

The Deceiving Staistics

Organized data has much importance as many organizations, research, and nations decide by interpretation of this data. But there exists a problem with that; any set of statistics might have something lurking inside. Something which can change the results totally, upside down.

For example, imagine that you need to choose a hospital for a relative's surgery from Hospitals A and B. Data so far shows, out of 1000 patients admitted in Hospitals, 900 survived (900/1000) in hospital A while 800 survived (800/1000) in hospital B. So, it looks like Hospital A is a better choice. 

But remember, not all patients arrive at the hospital with the same level of health. If we divide the hospital's last one thousand patients in good and poor health, the picture seems completely different. 

Hospital A had only 100 patients who arrived in poor health, out of which only 30 survived (30/100), but hospital B had 400, and they were able to save 210 (210/400). So, hospital B is a better choice for people arriving in poor health with a survival rate of 52.5%. 


And if the health of the patient arriving in hospital B is good, then, strangely enough, Hospital B is still the better choice with a survival rate of over 98%. So, how can Hospital A have an overall survival rate if Hospital B has a better survival rate for patients in each of the two groups??


What we stumbled upon is Simpson's Paradox. Simpson's paradox occurs when data groups show one particular trend, but this trend is reversed when the groups are combined together. This often happens when aggregated data hides a conditional variable, which is a hidden factor that significantly influences data.  


So how do we avoid falling for the paradox?

Data can be grouped in many ways, and overall numbers can sometimes give a more accurate picture than data divided into various categories. All we can do is carefully study the actual situation statistics describes and consider whether the lurking variable may be present. Otherwise, we will be vulnerable to being exploited, and others may manipulate and use data to achieve their agenda. 

That's a wrap -- Thank you for reading!

Comments

Popular

Frugal Science: Science for all

 Science is not just about knowing but also about experiencing.  Today with the boon of technological advancement we have easy access to information and knowledge which is merely a click away. Science is largely about learning and it comes through the experience. So, it's more important how you can make the experience of science more accessible to a lot of people around the world.  The actual experience of science is utilizing scientific tools to make your own discoveries. Prof. Manu Prakash at Stanford University is in a quest of how can we make scientific tools that are so affordable, which are like buying a pencil from a shop, So what it would mean if a scientific tool is as accessible as pencil? What you would actually do, would you sketch with it or would you write a poetry with it, what exactly is the end of that for science? Prakash Lab do this in different fields but mainly focusing on the microscopic world. So how do you make the microscopic world easily visible,...

Remember to Sleep, Sleep to Remember

Sleep occupies nearly a third of our lives, but many of us give surprisingly little attention to it. This neglect is often the result of major misunderstandings. Sleep isn't lost time or a way to rest when all of our work is done. Instead, it's a critical function during which our body balances and regulates vital systems, affecting respiration and controlling right from circulation, growth, and immune response.  But, we care more about that test which we have tomorrow morning, right? One should certainly not; it turns out that sleep is also very crucial for the brain, with a fifth of the body's circulatory blood being channeled to it when you are drift off. And, what goes on in our brain while we sleep is an intensely active period of restructuring, which is crucial for memory function.  According to psychologist Herman Ebbinghaus, we usually forget 40% of new material within the first 20 minutes, known as the forgetting curve. But fortunately, this loss can be prevented b...

Foldscope: The Paper Microscope

 Foldscope is an ultra-affordable paper microscope which can be folded with a sheet of paper.  Foldscope is created with a vision to solve the accessibility problem in Science. It is designed to be portable and durable while performing on par with conventional research microscopes ( 140X magnification and 2 micron resolution ). Foldscope which began as a simple idea has now grown into a company that provides low cost tools to communities around the world to discover the world around and interpret it their own way.  A foldscope is an optical microscope that can be assembled using simple components like sheet of papers and lens. It is developed by Manu Prakash and designed to cost less than US$1 to build. It is the part of the frugal science movement which aims to make cheap and easy tools available for scientific use in the developing world. The mission is to break down the price barrier between people and the curiosity and the excitement of scientific exploration! With t...