Digna Legi / Watch · 31 October 2026 · Selection 04

Five ways to test what matters.

A ceiling on research spending, a rough prototype that rejects an idea, a distinction about worthwhile work, a way to retain what you learn and an ordinary object with hidden engineering. Choose one question to follow.

If you watch only one

Unit 9: Value of Information, Video 4: Expected Value of Perfect Information from 3:00 ↗ In four minutes, a raincoat decision makes the value of perfect information concrete: work out the improvement over the best decision you can already make.

01Underseen

Decision analysis · MIT OpenCourseWare · Full runtime 11:43

Unit 9: Value of Information, Video 4: Expected Value of Perfect Information

Richard de Neufville · MIT OpenCourseWare

The idea Perfect information is worth only the improvement over the best decision you can already make.

Why spend the time A raincoat decision tree makes the calculation visible: compare the best choice without a forecast with the best state-dependent choices after a perfect forecast, then subtract. Before buying another test, ask whether even perfect information could justify its cost.

Reservation This is an upper bound, not a promise that a real test is useful. Its probabilities and payoffs must fit the decision; a cost below the bound does not establish value.

Suggested passage: 3:00–7:09

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Product design · TED-Ed · Full runtime 8:08

Rapid prototyping Google Glass - Tom Chi

Tom Chi · TED-Ed

The idea A rough physical proxy can test an interaction before you build the technology that would deliver it.

Why spend the time Chi shows a projected display and a fishing-line gesture rig made from everyday materials. The second prototype helped his team reject an awkward interaction. Name one experience your proposal depends on, then build the cheapest proxy that lets someone actually try it.

Reservation These are first-person development examples, not controlled evidence that prototyping makes every team faster. Testing an interaction does not validate market demand, privacy or social acceptance.

Suggested passage: 1:03–4:35

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03Underseen

Philosophy · EconTalk · Full runtime 1:39:22

Kieran Setiya on Midlife 9/19/22

Kieran Setiya and Russ Roberts · EconTalk

The idea Finishing a worthwhile project ends one source of meaning; an ongoing activity can be valuable while you are doing it.

Why spend the time Roberts presses the distinction with marriage, parenting and writing. Setiya clarifies that the same action can serve a goal and sustain an ongoing relationship. Consider what you value in your work besides reaching its next endpoint.

Reservation This is a philosophical distinction, not a treatment or a reason to abandon obligations. The discussion acknowledges that changing perspective alone may not undo social pressure or emotional habits.

Suggested passage: 14:10–30:01

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Learning science · Faculty of Science - McMaster University · Full runtime 51:22

John Dunlosky -- "Improving Student Success: Some Principles from Cognitive Science"

John Dunlosky · Faculty of Science - McMaster University

The idea A correct answer today is not the end of learning: retrieve it successfully again in later sessions.

Why spend the time Dunlosky turns notes into questions, adds corrective feedback and combines retrieval with spacing. Try recalling one concept without looking, check its meaning against the source, then revisit it on another day. Later experiments in the talk separate immediate success from durable retention.

Reservation Benefits depend on the material, feedback and practice schedule. The classroom examples do not establish equal gains for every complex skill, and the older lecture is not a current assessment of education systems.

Suggested passage: 24:45–35:17

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Engineering · engineerguy · Full runtime 11:38

The Ingenious Design of the Aluminum Beverage Can

Bill Hammack · engineerguy

The idea A familiar shape is a compromise among material, packing, manufacture and use; even the tab changes its mechanical role as it opens.

Why spend the time Physical samples, cutaways and slow-motion diagrams explain why a can is cylindrical, how its seam seals and how the tab first vents pressure before pushing the opening inward. The object becomes a compact lesson in competing design constraints.

Reservation The film describes a particular can design and a historical manufacturing process. Its production statistics are dated; the simplified lever diagram is not a complete stress analysis. Rexam supplied the manufacturing samples, which the film discloses.

Suggested passage: 0:00–10:20

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