The Mom Test book: how to interview your target

the mom test

Table of Contents

The Mom Test is a book written by Rob Fitzpatrick – an entrepreneur for over 10 years – whose purpose is to communicate to startup founders (or aspiring ones) the best way to address their target in the validation phase of their idea.

By following this guide, you will be able to obtain real data, to understand if your idea is valid, on which market to place it, which target to address, if the target will be willing to pay for your product, and much more.

Therefore, in this article we will delve into what “The Mom Test” is, what it consists of, and which phases it breaks down into, going into the details of the latter.

The Mom Test

“The Mom Test”, as previously mentioned, is a guide on how to manage interviews during the validation phase of the idea. In fact, the book provides practical examples of conversations you might have with potential customers, showing why in some cases they work and in other don’t and, consequently, which questions would be best to ask and which to avoid.

However, the best way to understand what this book is all about is to explain where its name comes from: “The Mom Test” comes from the premise that you should never ask your mom what she thinks of your business because, almost certainly, she will tell you a lie. Likewise, you should never ask anyone what they think about your business because everyone will lie to you, and you will end up collecting false data.

To prevent this from happening, the author of “The Mom Test” has identified three rules to always keep in mind:

  • Ask the target about their life, never talking about your idea.
  • Ask about specific moments in their life, rather than asking general questions or asking for opinions about the future.
  • Talk less and listen more.

By following these simple rules, you will already be able to identify the real problem of your target, their interests, and their goals. As a result, you will know if your solution really addresses their problem and if they are interested in buying your product.

To better understand the previous rules, we can divide the entire process into two main phases:

  • The learning phase
  • The confirmation phase

The Mom Test: the learning phase

At this stage of “The Mom Test”, it is more important than ever to keep in mind the rules we mentioned in the previous paragraph. In fact, it is the moment to dedicate yourselves to the interviewees without ever telling your idea. In this way, you will collect important data about their lives, which are essential before moving on to the next confirmation phase.

Below, we analyse what this phase consists of:

  • the “behaviours to follow”, and 
  • the “bad data” to pay attention to.

The behaviours to follow

When conducting an interview, there are behaviours that should be kept in mind to ensure that the target feels at ease and, above all, doesn’t feel compelled to lie.

Such behaviours, as “The Mom Test” suggests, are the following:

  • Stop seeking approval
  • Create a list of 3 questions
  • Be causal and avoid formalities

Below, we take a closer look at these behaviours.


As we will see later, compliments must be considered as a dangerous element that often comes from one’s need to seek approval. When this behaviour occurs in a conscious way, you are exposing your ego and making one of the mistakes listed in the main rules: you are talking about your idea in search of consensus and compliments.

As much as we may consider this behaviour normal when you are particularly enthusiastic about your idea, it would be better to put your ego aside and focus on the other person asking about their life and their goals. In fact, according to “The Mom Test”, people rarely tend to lie when asked about something specific.

3 Questions

To avoid getting in trouble during an interview, you can consider the idea of preparing a list of 3 questions to ask your interviewees. In this way, you will be sure to ask questions “approved” by “The Mom Test”.

Once you have collected enough data with the answers obtained from these questions, you can also create another list of 3 questions to ask subsequent interviewees. This will serve you, at the end of all the interviews, to have a more complete picture.

Being casual

Being casual, i.e., conducting the interview as if it were a chat with a friend, is one of the behaviours recommended by “The Mom Test” that will allow you to prevent people from telling you lies and – not least – in the best case it will allow you to create real contacts that will be useful to you at a later stage.

The “bad data”

The second chapter of “The Mom Test” deals with the topic of “bad data”, i.e., data that we are led to consider true and represent a risk for your business.

Specifically, there are three types of “bad data”:

  • The compliments
  • The fluff
  • The ideas
The compliments

It might sound strange to think that compliments should be considered as bad, but in these circumstances a compliment is, in most cases, a lie.

However, by avoiding talking about your idea and immediately proposing your solution as the best to the problem mentioned by the target, you will avoid fake compliments and, on the contrary, you will collect important information on how and if the target manages the problem and how much your solution to the problem would change their life.

The fluff

There are three different types of fluff:

  • Generic claims (usually, always, never…)
  • Future-tense promises (I would, I will…).
  • Hypothetical maybes (I might, I could…).

To avoid receiving answers that could be categorized in the previous list, remember the three main rules of “The Mom Test” and try to ask specific questions, so that your target cannot answer in a generic way.

The ideas

During an interview, it may happen that the roles are exchanged, and it is your target who gives you ideas as a solution to their problem. Surely, this is good news because it means that they see potential in you. However, although it is important to take these ideas into consideration, keep in mind that you must focus on your idea and no other’s.

Therefore, according to “The Mom Test”, what you can do in this case is to examine why your target has thought of that solution and you can do it by asking questions such as:

  • Why do you want it?
  • What would it allow you to do?
  • How would it become part of your life?
  • Tell me more.

The Mom Test: the confirmation phase

At this point you have collected enough data to create an identikit of your buyer persona and proceed with the confirmation phase.

In this second phase of “The Mom Test”, the rules change, and the goal is to create engagement to make sure you have customers when your product will be launched on the market.

Therefore, below we go into the details of this phase.

Commitment and advancement

The confirmation phase of “The Mom Test” is the moment in which your target begins to show you commitment and advancement because you will begin to expose your idea and to show a prototype of your product.

First, it is necessary to make a distinction between the concept of commitment and the one of advancement:

  • Commitment: your target shows you they are interested by dedicating their time, reputation, or money to you.
  • Advancement: your target provides you with confirmation that they are willing to buy your product.

Often the concepts of commitment and advancement go hand in hand, but in other cases it may happen that neither of them occurs. In that case, “The Mom Test” teaches that you don’t need to scream at failure because you still have time to fix it. You can take a step back, i.e., go back to the learning phase to understand what went wrong, make the necessary changes, and repeat the confirmation phase.

Causes of failure

Among the main causes of failure of this phase of “The Mom Test”, we can identify two main ones:

  • You asked for an opinion on your idea, i.e., you pushed your interlocutor to compliment you.
  • You did not ask clearly if they were willing to show commitment to your idea.

In the first case, we already know that the best way to get around a compliment is to ignore it and try to figure out if it is just fluff or you can still do something to get the interlocutor’s commitment.

In the second case, according to “The Mom Test”, the situation is much serious. It could happen that you avoid asking for a commitment from the target for fear of failure or because you don’t know how to proceed, but at the same time not asking for it is already a failure for you and your startup. Therefore, it is important to always have clear ideas about what the next steps will be and take the risk of asking the interlocutor to sacrifice some of his/her time, reputation, or money for you.


“The Mom Test” represents the best guide to follow during a customer’s interview to obtain valid and effective results in the validation phase of your startup’s idea. For this reason, in this article we have summed up the main steps and rules and reiterated the mistakes to avoid.

However, we invite you to further explore the subject by reading “The Mom Test” by Rob Fitzpatrick, of which we leave you a link to purchase.

If you are interested in customers interviews, please also read Interviews with customers: tips to validate your startup idea and find out more on Validate your startup idea page. You will discover more interesting content and videos to watch!