Estimation: Clarify, Approach and Validate
When I find alternative approaches to answer product case questions, I share them. While I have my preferred methodologies, I am always willing to share other approaches, in the event they help my clients.
In this article, Sri Gari (an ex-Googler) shares his approach to estimation questions. He even includes a video.
The Methodology
Clarify. Make sure you understand the core components of the question
Approach. Mathematical approaches to the problem
Validate. Sanity Check your answer.
Mathematical Approach
Mathematical formula: Equation to be used for computing the answer.
Breakdown: Break into multiple variables and compute them separately.
Substitution: Plug in numbers into the formula.
Calculate: Do the math to compute the final answer.
Estimation Question Types
Sizing. Think market size or amount of storage needed.
Volume. Number of X in Y. Think number of restaurants in a city.
Examples Provided
What is the market size of the refrigeration industry?
How many kayaks do you need for your startup in Seattle?
Tips & Tricks
This includes many of the same tips & tricks I share in my methodology as well.
Clarify anything ambiguous. (See my advice on diagraming prompts, it applies.)
More than one solution.
Round numbers.
Keep track of units.
Use symbols.
Double check: Always sanity check
