aharish.xyz

Approaching a Guesstimate

3 min read

Steps

  1. Take a step back and think through the question - the interviewer is not looking how fast you can solve, but how well you can solve it
    1. Take time to think about the question
    2. Don’t rush to answer
    3. Understand the question completely
    4. Think about the final answer
  2. Breaking down a question into smaller pieces and solving each piece
    1. Identify the type of guesstimate

      1. Shape based: If the guesstimate is shape based, then break it down into a simple geometrical or mathematical solution. Use the formulae for area, volume, distance, etc.

      2. Market Sizing: Take either the demand side or the supply side.

        The demand side is typically used where you have a clear idea of what your customer might look like. Customers are generally classified using data on population, income group, gender, etc.

        The supply side is used where the product is limited: eg. plumber can only work certain hours a day, or a metro will work only certain hours a day. This is generally known as a rate determining step. This is the slowest step in the whole project and think about it to make sure that you never exceed this step

        For the abstract side, you will have to understand the question and try to figure out how to bring it down to the size of the first two steps. For eg.: How many trees are there in the Amazon Rainforest - here you would have to make use of the geometrical approach and the constraint approach - there can only be so many trees in the unit area and you can arrive at the total number of trees. One other thing that you can use here is proxies, which are basically replacing one unknown parameter with a comparable unknown - for eg.: you can compare the Amazon Rainforest to your knowledge of the Sunderbans to know the relation of the areas in the two. So if you are asked to find out the number of shoppers in Khan Market, but you have never been there, you can take a comparable market that you know of, figure out the number of shoppers there, factor in the criteria of difference between the two markets and arrive at the final number.

  3. Once you have decided what the framework of your guesstimate is going to look like, discuss it with your interviewer.
  4. Make sure you both are aligned on the same approach.
  5. The interviewer might point out feedback to bring the approach to the right track or they might tell you the parts that are insignificant and need not be considered.
  6. The interviewer will most likely try to help you in honing your approach. Therefore it is very important to get them on board with your solution early on.

Example Guesstimate Interview - How To Approach Guesstimate

Graph View

Backlinks