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Students are given a strategy for more adaptively and flexibly getting to their goal “destinations,” namely, by looking more deeply at their WHY to widen their HOW.




MATERIALS NEEDED: Whiteboard work surfaces and dry-erase markers (or large sheets of paper)


intro video



When navigators from the Polynesian Voyaging Society are planning a voyage from Hawai'i to Tahiti (2,500 nautical miles across open ocean!), they don’t aim directly for Tahiti. Tahiti is only 28 miles wide and would be incredibly hard to navigate directly to. (Most trained navigators know where they are within 50-100 miles on long open ocean voyages such as this). Instead, navigators aim for a fan of islands in the Tuamotu Archipelago that extends east from Tahiti.  This is sometimes referred to as a “cone of error” (see whiteboard sketch below) because it gives the navigators some room for error on their 2,500 nautical mile open-ocean voyage.  It means there are an infinite number of paths a canoe could take within this cone that successfully lead the navigator and crew to their destination, because once navigators hit any one of the islands along the fan, they can orient themselves easily and head towards Tahiti.  As our friends at PVS described it, wayfinders are smart about picking “waypoints that allow for flexibility and are generous to the self.”  In the case of sailing to the island of Tahiti, the fan or “cone” that navigators aim for is about 150 nautical miles wide!  That’s quite a wide target, but still an incredible feat after such a long voyage.

A rough whiteboard sketch of the "Cone of Error" principle done by navigator Jenna Ishii from PVS.

A rough whiteboard sketch of the "Cone of Error" principle done by navigator Jenna Ishii from PVS.

Navigators also do a tremendous amount of planning before making a voyage.  They design a Reference Course as part of their course strategy, which represents the idealized, linear path the canoe would sail given average wind, currents, and weather conditions anticipated along the way (see example at right). However, as described on a PVS web page:  “It is highly unlikely that the canoe will stay on the reference course because wind direction will vary along the way, and the canoe can only sail in the direction the wind allows it to sail. The art of wayfinding involves adapting to variable and unexpected conditions of wind and weather while maintaining progress towards the windward side of the targeted islands.”  In this example for the 1992 voyage from Rarotonga to Hawai‘i, the reference course is represented by a dotted line , with the actual daily positions (x) and the navigator's estimates of position (o) at sunrises.

 Source: PVS page: “Designing a Course Strategy

The general technique of why-how laddering is a method often used in design thinking as a way to think through a hierarchy of needs for users.  (see the link below in our Resources section)  You can use it to extrapolate up to higher-level needs if your need is too narrow/specific, or to distill down to more actionable/concrete needs if your need is too general/big-picture.


Media and Story resources

  • K12 lab resource page on why-how laddering as a general strategy for thinking about user needs
  • See Bootcamp Bootleg method card about why-how laddering (also appears at the end of our Facilitation Guide)


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