How is the Global Intentional Index measured?

One question, one number

The Global Intentional Index, also called Intentional Nights, counts one thing: out of 100 kids, how many slept last night with a phone in the room. The number shown is the share of kids under 18 who did, averaged over all the nights reported in the time window. It is an average night, not the figure for one specific night. Lower is better.

A night without a phone in the room is an intentional night, and the two always add up to 100. If 34 out of 100 kids slept with a phone in the room, 66 had an intentional night. The index stores intentional nights, and the pages show the other side.

What each word means

The definitions are fixed so that everyone answers the same question.

• Kid: anyone under 18.
• Phone: a mobile phone. Tablets and watches are not counted.
• In the room: in the room where the kid fell asleep. A phone on a shelf or charging still counts as in the room.
• No phone at all: a kid who has no phone counts as no phone in the room, which is an intentional night.
• Last night: the most recent night that has ended, named by its evening date.

A second question measures intent: where do you think the phone should sleep? The gap between what people want and what happened last night is part of the story.

Who answers

Everyone can answer. Parents answer about their kids under 18 who live with them, teens answer about themselves, and adults answer about themselves. The headline number, the one about kids, is built from parents and teens. Adults are a second, separate number.

Where the answers come from

Answers arrive from four places.

• Web: the anonymous questionnaire on the index page.
• Field: short street interviews. Answers are written down without names, and an answer the team is unsure about is checked by hand before it counts.
• Events: the same questions, answered at talks and events.
• ZUZA: people who use the ZUZA app can choose to share. Only national totals per night arrive, never a user.

Web, field and event answers count in the headline, and every answer keeps its source tag so any view can be filtered by source. The ZUZA layer is separate and is never mixed into the headline number. In that layer, a phone docked in a ZUZA dock outside the room for at least 70% of the 23:00 to 06:00 window counts as no phone in the room.

There is a disclosure that belongs next to this. Beeri Tzori, who runs the index, also founded ZUZA, a company that makes a phone dock. That is why the ZUZA data stays a separate layer and why the questions and the method are public.

How the number is computed

Each parent answer adds the kids it reports. Each teen answer adds one kid. Then the index is 100 times the kids with an intentional night, divided by all the kids reported, rounded. The number shown is 100 minus that.

An example from the method page: a parent of three kids, one of them with a phone in the room, plus a teen whose phone slept outside the room. Three of four kids had an intentional night, so the index is 75, and the number shown is 25.

The 10-answer threshold

A country shows a number only after at least 10 answers for that series and time window. Until then the page shows how many answers were collected. Between 10 and 99 answers, the number is labeled an early estimate. With 10 answers, the true share can be about 30 points away in either direction, so ten is a floor against noise, not a promise of accuracy.

The default view is the last 90 days, which follows change. Two other views exist: all time, and a weekly trend grouped by ISO week.

The known biases

The method page lists them openly, and they matter.

• People who care about phones at night are more likely to answer.
• Web answers come from people who reached the site, mostly through social media.
• Some street interviews were with families on vacation, and a night away from home is not a typical night. Those answers are tagged.
• Parents and teens report differently. A parent may not know where the phone was.
• A country is suggested from the network the answer comes from, so travellers and VPN users can be counted in the wrong country unless they correct it.
• Even above 10 answers, one country can move a lot from week to week.
• Some people give the answer they think is right, not what happened.

The method states the consequence plainly: this is not a representative survey of any country. It is a public count of the answers we have.

Privacy and versions

The index does not store an IP address, email, cookies or any device ID. It keeps the answers, the country code, the questionnaire language and where the visitor came from, for example a QR code, with the time rounded to the hour. Kids can answer, so nothing that identifies a person is collected.

This is method v1. Every answer is stored with the version it was given under, and numbers from different versions are not mixed without saying so. On 14 October 2026 the question was turned around to "with a phone in the room"; what is computed and stored did not change. There is no data download yet.

You can see how it looks and add an answer, three taps and under 30 seconds, on the Global Intentional Index page.