The Probability Of Being Successful on Medium
How the Prior Probability Influences Our Projects
I need to understand it, and you can help me out.
Recently, I’ve started reading the book: “Thinking fast and slow” by Daniel Kahneman.
And I got an illumination reading about “Prior Probability” vs “Conditional Probability”.
So, curiously I wanted to apply this knowledge, and I asked myself:
“What is the probability that I’ll become a successful writer on Medium?”
Since we are talking about me, let me think about my skills:
- I like writing, which increases the probability
- I’m a reflexive person, which increases the probability
- Not much creative maybe. Let’s call it a decrease.
- And yeah, I try to be much constant as possible. And I know that this step requires effort. Ergo, I’m not much willing to give up on difficulties. The probability increases.
What is the probability then? Shall we say 20%?
I met a lot of writers, and they have similar skills. This would increase the probability, wouldn’t it?
Then, I would increase it, like to 50%.
So, why does “50%” sound so crazy when I say it out loud?
Daniel Kahneman gave me an answer to this: we need to consider the Prior Probability.
The Prior Probability
The Prior Probability is the probability without any other information.
In this case, the Prior Probability is “What is the probability of becoming successful on Medium?”
Forgetting about all my skills.
Conditioned Probability
Now we introduce a new variant: my skills.
New information. The probability changes. Now our probability is conditioned to our specific case.
The Bayes Theorem
- P(A) = Probability to be successful on medium (Prior Probability)
- P(B) = Probability of having these skills
- P(A/B) = Probability of being successful having these skills
- P(B/A) = Probability of having these skills if you are a successful writer
From this formula, we understand that the Probability of being successful on Medium having these skills is directly proportional to the Prior Probability.
This means, no matter how many skills we can have: if the Prior Probability (= being successful on Medium) is low, this will make decrease the Conditioned Probability (= being successful on Medium having these skills)
External Opinion (Get Some Data)
Daniel Kahneman says that we always forget about Prior Probability.
We focus too much on our specific case, unknowingly increasing the probability to be successful in something: in doing that project, passing the exam, or whatever.
So, if you wanna jump into a long-term project, ask yourself: “Forgetting all my skills (or the skills of the team), what are the chances that a project like mine will be successful?”
Collecting data about similar projects or asking for an external opinion from an expert that gave us the probability for this project to be successful, can be a good idea.
If the Prior Probability is very low, it’s maybe not a good idea to start this project
0.5%
I don’t know the probability of being successful on Medium.
But let’s say that the probability is 1% = 0.01
If the probability of having these skills and being successful on Medium is 50% = 0.5
The upper part of the equation is: 0.5 * 0.01 = 0.005 = 0.5%
We decreased the numerator from 50% to 0.5%
Why We Forget About The Prior Probability
As Daniel Kahneman says, when we have an idea we overestimate our probability of success.
We imagine ourselves in a successful scenario that is not going to happen.
Our imagination is our enemy.
We also underestimate the costs of a project.
So, imagine starting a project (very unlikely to have the expected success) with an underestimated budget.
When we finish that budget but not the project, we are in a dilemma: invest more money and keep working on the project or fail.
At that point, the first option is the most chosen one.
In the end, this scenario brings us to have projects that cost much more than expected with lower results.
