How to Turn a WAG (Wild-Ass-Guess) Into a SWAG (Scientific-Wild-Ass-Guess)
Next in our Providing Meaningful Estimates series we talk about turning WAGs into SWAGs.
S-W-A-G stands for a Scientific Wild Ass Guess. It’s sometimes used more as a tongue-in-cheek way of saying: “This estimate isn’t really reliable. I pulled it out of the air.”
I’m going to show you how to put the S — the science — back in a WAG so even an off-the-cuff estimate can be meaningful and useful to your audience. The easiest way for me to demonstrate how to improve your SWAGs is to use a simple example.
Consider providing a SWAG, an order of magnitude estimate, on how long it would take you to read to The Fountainhead (752 pages) by Ann Rynd. In fact, stop reading this article right now and come up with your estimate. Please don’t do any research. Just take a moment and give me your “best” wild-ass-guess (WAG) right now. I’ll pause for a sec.
No seriously, take a moment, and come up with how many days it would take you? 1, 7, 14,…… 365? Just take a moment.
Now, I’m going to l give you a technique that to add some S to your WAG and make it a more a scientific answer.
Actually, It’s All In the “Words” We Use When We Present to Provide Our Estimates.
Whenever someone asks you for high-level-estimate and you can’t really do proper research, you will need to make assumptions. The key is to expose these assumptions with your estimate and to demonstrate how changes in assumptions might impact your estimate.
Here’s a framework that demonstrates how this works:
- When providing an estimate, always provide a range. And for each number in the range, provide assumptions. It sounds simple, but the difference is pretty significant.Always start out by thinking: What is the lowest reasonable number your estimate might be. More importantly, explain provide why do you think it is unreasonable to assume that the estimate might be lower.So for The Fountainhead, you might start the estimate with:“I can’t imagine it taking me less than 7 or 8 days. Assuming I find the book interesting, I can probably read 100 pages a day and a little more on the weekend. But with my workload at work, and errands in the evening, it’s not realistic to expect me to read more than 100 pages or so each day during the week.”
- Next, think about what is realistically the longest this task should take you. When you give this estimate, you also share what assumptions need to be true for you stay within this estimate (not exceed your high number).Returning to our example with The Fountainhead, you might continue your estimate with:“I can’t imagine it taking me more than 40 days. If it does take longer, then the book must have been written in a 3-point font or in French (I don’t speak French) or a crisis at work came up. I have to believe that I could force myself to read 20 pages a day, and even if I find it boring, I’ll get through the book in 35 to 40 days.”
Wild Ass Guess Vs. Scientific Wild Ass Guess
Now, let’s contrast these approaches in terms of reading The Fountainhead- a. All 752 pages.
WAG: It might take me anywhere from 7 days (a week) to 30 days (a month).
Using our new framework, you would answer:
SWAG: “I can’t imagine it will take me less than 7 days, assuming life doesn’t throw me any unexpected curveballs and I can read 100 pages a day. I can see it taking me as long as 38 or 40 days if I can only get through 20 pages a day due to boring content or unexpected crises at work. If it takes me longer than 40 days, then it not only was painfully boring, it probably is written in some ridiculous font or written in French (I don’t know French).”
I hope you agree, that the second example provides a level of confidence that we thought through our WAG and have some reasoning behind our estimate.
Check Assumptions. Manage Expectations.
The correct wrap up for a SWAG is an opportunity to further manage expectations by saying:
“If The Fountainhead is as good a book as you say it is, , then let’s assume I’ll get it done in about 14 days. Within the first 2 or 3 days, I can update you on whether this was a reasonable swag or not.”
This means within the first 2 or 3 days, you determine if the SWAG assumptions are correct. You can even restate your SWAG now that you have started reading it and verified your assumptions (one way or another).
If you still aren’t convinced, let me show you how effective this approach can be might be by by using a one more example real life example.
A Real SWAG in Every Day Life.
You own a home and want to build a deck on the back of your house. You ask two contractors to come out to your house and give you bids on the work. With each of the contractors, you walk through the backyard and show them where you want the deck. They show you different styles of decks and after reviewing the pictures, you choose your preference.
Each contractor tells you they will give you an exact estimate for cost and a proposal by the end of the week. But you have a key question: Your son is graduating college in two weeks and you want to know if the deck will be completed in time for the graduation.
Contractor #1 answers:
WAG: “The deck could take anywhere from 2 to 5 days. So if we start Monday we should have it done by the weekend. Let’s just hope we don’t get any bad weather.”
Are you at all nervous that the deck will not be done in time?
Contractor #2 answers:
SWAG: “I can’t imagine it taking less than 2½ days. If we can get the deck primarily built the first day, we’ll need the 2nd day to stain, make final adjustments etc. So by the time it’s dry and tweaked we are at the 2 or 3 day mark. It’s important that we don’t get any rain on Tuesday when we stain the deck.
Sometimes when we put the “supports” in the ground, we find obstructions we need to move. That could make the job take up to 5 days. If it takes longer than 5 days, then you have a surprise waiting under the ground. I don’t think you do, but until we start the job, I can’t be 100% sure. Of course, this assumes the weather doesn’t blindside both of us.
So barring any golden surprises, we should be able to complete the job between 2 to 5 days. I would hope to have it wrapped up by day 3 but I’ll know more on Monday.”
Which contractor gives you more confidence in their ability to deliver on what they said?
More importantly, if the estimates are off, they can talk with meaning. They can discuss what assumptions were wrong, or what had they not considered. In other words, it doesn’t feel like they just pulled a number out of the air without any thought or real consideration.
In summary: The Framework
So, in order to turn your WAG into a SWAG, start your estimate with:
- The shortest or lowest estimate that is reasonable
- Why it isn’t reasonable to be shorter/lower
- Explain how large it is possible to go
- What are the assumptions that would make it go that large
- What are your assumptions that could cause it to larger
- Finish your estimate with a viable, in between reasonable “target” in between that you believe is reasonable to start with. Explain how and when you will be able to validate assumptions and firm up your estimate.
Category: Defining Success, For Practitioners
I see what you mean by “scientific”. But by providing so much details isn’t the SWAG by contractor #2 the actual estimate already? In my books, that is not a wild guess anymore – it is a very decent guess.
I’ve always heard “SWAG” defined as “Stupid Wild Ass Guess”. I might add that the “WAG” in your example, being shorter and to the point, is far more likely to be useful in practice than the rambling so-called “SWAG” given for contrast.