What a One-Way Mirror in a Kao Lab Taught Me About Product Research

The longer I spend making products, the more I notice something about the strongest brands in this industry: the place they spend the most freely is usually not marketing. It is studying people.

A veteran engineer told me about something he saw with his own eyes at Kao's research center in Japan. To study baby diapers, they built a large playroom — toys, crawling equipment, everything a baby could want — and invited mothers from the surrounding community to come spend the day with their children. At the back of the room: a wall of one-way glass. Behind the glass, the laboratory. Researchers watched how each child crawled, rolled, moved, and played; how long the diaper was worn and to what degree of loading; then took the used diaper straight back for analysis.

What they were actually studying

Notice what is not happening in that room. Nobody is measuring "how absorbent is this material." They are studying what an eight-month-old's real day looks like — when he rolls, when he urinates, how much, in what position, under what activity. The product requirements are then derived backward from the behavior of a real human being.

That inverted order — person first, specification second — is worth more than any impressive lab number.

The habit we copied

Many companies do the reverse: close the door, study materials, study parameters, make the numbers look good. But the product is used by a person whose day you have never watched. What is the number for?

When we design, we force ourselves to script the user's day first. For our school-age line: when does a student have class, when can she reach a bathroom, what pants is she wearing, what embarrassment is she most afraid of. For period pants: what is a woman most afraid of at night — leaking, stuffiness, side leakage when she turns over. Get the person's details right down to the bone, and the product design mostly writes itself. We start every project by deciding who it is for; the Kao story is where that conviction came from.

For brands partnering with a sanitary pad manufacturer on OEM development, the practical version is simple: before discussing materials or pricing, describe your target user's actual day. A factory that asks about her day before asking about your target price is doing product development. The other order is just manufacturing.

Li Genyuan is the founder of Hunan Nafei Biotechnology, an OEM/ODM manufacturer of sanitary pads and menstrual pants. More from Founder's Notes.