Design Sprint Day 4: Prototype

Hopefully the team is feeling good the morning after Day 2 (Ideate) of the design sprint. It is now time to focus on the idea sketches that have yet to be revealed.


Disclosure: As mentioned in previous posts, the design sprint process varies based on the specifics of the actual challenge. For this reason, we will be covering a number of best practices that are used on Day 3 to better understand the challenge at hand, not the one and only way to execute Day 3.




Remember, the design sprint team is still in the dark about each other’s ideas. This is all about to change. The idea sketches should be taped on one wall, nicely spread out. The identity of each idea author will remain anonymous.


Instead of formally presenting the ideas, team members will explore each of them in silence, just like interested tourists intellectually exploring a science exhibit or art museum. The only thing that may be different about this exhibit is that it demands silence. There is no speaking. There are no questions.


During the exhibit, everyone has unlimited access to little dot stickers. Whenever someone finds an element of an idea sketch valuable, he or she places a dot in the region of the sketch that corresponds to that very element. Also, viewers at this “exhibit” should place two or three additional dots on the most promising ideas.


After twenty to thirty minutes, the idea sketches should be filled with clusters of dots, some with plenty of dots and others with few dots. The silence can now be broken.


Hasty Judgment


The team has a three to four-minute conversation about each idea sketch. The idea authors remain anonymous. These conversations start with the Facilitator briefly narrating a sketch for the rest of the room. It is also the Facilitator’s job to highlight those areas on each sketch that have the most votes (dot stickers).


Each time an idea is narrated, team members point out their favorite aspects of the idea and share questions and concerns. Even when questions are asked, the idea author must bite her tongue and conceal her identity.


Only after the the team has had a brief discussion about the idea’s strengths and weaknesses can the idea author step forward. She should share with the room any desired clarifications or idea features that were missed by others.


Throughout this entire process, there is a designated scribe to record standout idea elements. He should write down those elements with the most dot stickers and record those positive comments about each idea that seem most prevalent to the challenge. What does the scribe write these notes on? You guessed it… sticky notes! After the hasty judgment period is over, these sticky notes should be placed accordingly above each idea sketch.


Remember, it should be stressed by the Facilitator that each idea sketch should be discussed no longer than four minutes. Setting a timer for either three or four minutes and placing it at the front of the room is usually a good idea to keep the team moving forward.


To the Polls


The team must remind itself of the design sprint goals and then get ready for some more silence. Everyone has one large dot sticker to place on his or her favorite idea. However, to eliminate biases, have all team members privately write down their votes on paper. Voters should go for a viable and feasible idea that also contains some element of originality and risk. After ten minutes, assuming each member is ready, it is time to place the large dots.


After voting, the dots may or may not be clustered. Regardless, each team member will soon have one minute to explain his or her vote to the rest of the room.


The Chosen One


Believe it or not, that last vote didn’t decide which idea will be further explored with a prototype. This is because that decision is ultimately left to the Decider(s). The Decider has to choose which idea (or two) the team is going to run with during the second half of the design sprint.


This can, no doubt, be a stressful decision. However, everything that occurred thus far on Day 3 can act as a guide for the Decider. He can use the dots, the sticky notes, and all prior discussion to reach a conclusion. Conversely, he can ignore all dots and the rest of the team’s insights if he so chooses.


The important thing is that he arrives at the decision that he believes is the best. After all, the Decider is the individual within the organization that has the authority to actually carry out such an idea after the design sprint, so he needs to fully back it.


Note: There is a chance that the Decider believes two ideas are equally great and should be tested over the following two days. This can be done. Either amend the two remaining ideas into one, or prototype and test them separately.




Now that a decision was made, it is time for the team to sketch out the final solution in more detail. This is in preparation for building the more tangible prototype tomorrow. Keep in mind, the team may choose to borrow elements from other ideas while determining the specifics of the one being prototyped.


So, what exactly is a storyboard? It is exactly what it sounds like: the proposed solution drawn out in a way that tells a narrative of how it works. This is an eight to fifteen panel drawing on the whiteboard that gives the team an opportunity to hash out the details of the idea. Each panel can have a mix of drawings and words further explaining features of the idea while exposing assumptions.



The main reason the storyboard is so effective is because it requires full understanding of the solution. It is an easy way to find and solve the loopholes of a particular idea while ensuring that the entire team is on the same page. Furthermore, a well thought out storyboard comes in handy on Day 4 when the team has just one day to build the prototype. 


Note: No matter who first “founded” the idea, it must be made known that the idea is now everyone’s. No one team member, other than the Decider, has authority over the idea or its specifics. It is ultimately the Decider’s role to step in whenever harder decisions about the solution come up. Even then, the Decider should pay close attention to the feedback and concerns raised by everyone else in the room. Every individual a part of the design sprint team is there for a reason.


Wait! We almost forgot to mention, if the idea doesn’t already have a catchy (but realistic) name, then give it one! This can be a quick, fun exercise; no need to get too stressed about it. Have everyone take ten minutes to individually brainstorm names on sticky notes, then use a series of dot voting to decide the winning name.


In total, an hour or two should be spent on the storyboard. And once this is complete, Day 3 is finished up. The team will reconvene in the morning to make a prototype.




By the end of Day 3, the team should be happy with how the week has progressed. The proposed solution is set, and now the design sprint shifts gears to find both validation and criticism of the final idea.


Other Resources


As always, if you’d like to know more about design sprints, we recommend you checkout Jake Knapp’s book, Sprint. Another useful source is Google Ventures’ page with articles on the process: Also, check in with us as we continue to add posts on the design sprint process.

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