How we manipulate data

without even knowing

Even if you are keen to base your decision on robust and solid data, or at least google results, you are most likely to make this mistake.

Our usual habit is to develop a quick opinion about something and then consciously search for the information, that supports our opinion.

Mother who made up one’s mind NOT to vaccinate her child is more likely to express interest in reading an article called “Vaccines cause autism” rather than the one with headline “Vaccines DO NOT cause autism”.

video from

It looks like, business analysis is even more likely to be affected by confirmation bias, than google search.

Professor and decision-making researcher Dan Lovallo believes that “Confirmation bias is probably the single biggest problem in business, because even the most sophisticated people get it wrong. People go out and they are collecting the data, and they do not realize they’re cooking the books”

Together with participants of my Storytelling with Business Data workshop we have noticed, that even on the same set of data, people have tendency to tell different stories, influenced by their original opinion.

Instead of changing our existing beliefs, based on the newly acquired data we tend to change the interpretation of that data to fit our beliefs.

If you want to tell the true story of your data, there are some confirmation bias alerts, you need to watch out for:

  • You know the conclusion of your analysis before you even start. Let’s say analysis request comes in a form of question: “Can you find some data to support that… ?”
  • You are requested to change the scope of your analysis: “What does the data show, if we look at the last quarter only?”, “What if we exclude these two categories?”
  • You are asked to change proportions or scale of your chart, for example ignore zero base, to “make the data more visible”

Quite often in my corporate career I met type of managers who, in the words of Andrew Lang, “used statistics as a drunken man uses lampposts—for support rather than illumination.”

Do not become one of then – always start with an open question.