Why are humans so bad at estimating?

Prediction is hard, especially if it’s about the future” — Yogi Berra

Most estimates are wrong most of the times.

Think about it, from the cost of renovating your flat to how long it’s going to take you to do your taxes to how much it’s going to cost to design that website, we’re all bad at this.

Deadlines, budgets and expectations don’t stand a chance when it comes to humans estimating things.

The good news is that everybody goes through this so you don’t have to be too hard on yourself. Not knowing exactly what the future’s got in store for you is one of the great things about life. It would be pretty boring otherwise.

We wanted to better understand why everybody’s so bad at estimating. Out of the many reasons out there, here are the ones we found most insightful:

1. We love to procrastinate

Hmm, an important-essay is due in 48 hours. This seems like the perfect time to start Season 2 of Lucifer.

You know what you have to do, but you wait until the last minute to do it, or you don’t do it at all.

This isn’t necessarily a sign of laziness or not giving a damn. In fact, most procrastinators are intelligent, hardworking, capable people who simply cannot finish tasks on time.

Researchers found out that the process of procrastinating comes from a deep fear of failure, of making mistakes. It’s not easy to overcome the fear of failure, but what you can do is start looking at things from a different perspective. So what if you fail?! Maybe it will make you stronger! Try to see failure as a necessary step on the road of success and everything will come naturally.

2. We tend to have incomplete recalls of previous experiences

Today was the second time I got to your place by getting lost the same way as last week.

The inner workings of our brain are to blame for this one. When we do things right, a neural pathway is created but the same happens when we do things wrong.

In short, by performing any type of action, we build habits, both good and bad through practice and repetition of thinking, feeling and acting. The reason we keep estimating badly is that we slip back into our existing neural pathways.

There are many things to do if you want to change the habits that harm you. One of the most effective is meditation because it forces your brain to break free from normal patterns entering a deep relaxation state. You can also repeat a behaviour (think positive thoughts) or exercise an action (learning a new language or a new instrument). This way, new neural pathways are created, replacing the older ones.

3. We are stuck in the Planning Fallacy

I was pretty convinced I could build Buster his dog house over the weekend. That was two weekends ago. I gave up and bought him a raincoat.

The term, first introduced by Daniel Kahneman and Amos Tversky in 1979, describes the phenomenon in which humans display an optimism bias when planning or evaluating things for the future.

The phenomenon only takes place with tasks that we have to do. The interesting thing is that if we are to estimate tasks made by others we tend to believe that they will take more time than they really should.

In short, the paper proposed by the two researchers says that humans are extremely bad at estimating.

The good news is that you can overcome planning fallacy by using past similar activities to guide your future estimates. Use your knowledge based on experience to plan similar tasks in the future.

4. We tend to have focus bias when estimating

"On Sale, 24 rolls of duct tape for just $29.99” — I sometimes use duct tape and this seems like a pretty good offer, why not?!

Anchoring is a cognitive bias described as our tendency to only focus attention on one aspect of a task and ignore the rest.

By focusing too much on one thing we tend to neglect other important factors thus, our predictions turn out to be inaccurate and unrealistic. There are several theories on how people can overcome anchoring, depending on their mood or how much information they are given.

One thing you can do is simply accept your vulnerability to anchoring and try to consciously observe your behaviour when you estimate. If you notice you’re drawn into anchoring, take a step back and force yourself to zoom out from that initial piece of information.

5. We are too optimistic and want to please others at all costs

Don’t worry, dear! We won’t have to stay with my parents much longer because our house renovations will be finished in one week.

People significantly underestimate the amount of time it will take them to complete tasks when there are others involved (colleague, client, spouse, you name it). We want to make a good impression so we tend to be much more optimistic, insinuating that we can do things faster because we are better. The paradox is that, by doing so, the estimate will be unrealistic, the outcome won’t meet expectations and people will be left disappointed.

So, the next time you estimate something, keep in mind that it is better to be honest with yourself and your partners so no one ends up frustrated.

Humans will always be naturally bad at estimating stuff. We can’t change that, but we can help you estimate things more accurately.

Specstimate will help you write better project requirements together with your clients and make more realistic estimates. All in a collaborative and transparent manner that inspires trust and professionalism.

If you are a freelancer or work in a digital agency you can sign up for Early Access on our website.

May your estimates forever be accurate!

P.S.: We estimated we'd be publishing this article by Tuesday. Hello Wednesday!