Instrumented People, Places and Things: candy bag, 2011
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Following a bag of candy. In May 2011 the Iota team, for a confections client, sent a kit to each of 20 teens and young adults in two US cities: a sensor pack to stick on a bag of candy, a GPS receiver to carry, and a pocket camera for short video stories. Everything here was logged in those people's own days. The anchor is a thing, with people and places beside it.
A proof of concept. The page asks whether the approach was viable, and what kind of picture it gives. It leads with cases and patterns. Its numbers describe these few people and bags and do not measure a population. In TJ's words: “instrumented candy bags, supplemented by location information, participant video, and interviews, offered a view of consumption across times and situations.” (Modeling Activity, p. 4)
One pack, many bags. Each person had one pack. They stuck it to a bag with adhesive dots, moved it to the next bag, and charged it at night. So the readings do not know which bag they come from, or how much candy is left, and nobody's purchase is in them. A bag's life appears only where the team's labels on the videos mark it: 63 stories from 16 people, which this page reads as 40 bags.
What the pack read. Touch, by capacitive sensing on six copper plates in its lid, and movement on three axes, with a clock and a memory card. The page draws them as the team's own viewer did: touch on six rows, moves in purple.
The model of activity. How a bag is eaten: in one sitting or not, at home or not, poured or picked. The readings reach the first two in part. They do not reach the third, which stays with the team's labels. The model stops there, and the Model view shows where.
Moments
A draft, November 2026. Participants appear under codes assigned here, by study day, with no dates, names, ages, addresses or map.
How it was drawn
- A bag
- As the team's data viewer, Iota Data View, drew it, an overall strip above a detail strip: video moments in blue, touch on six rows, moves as purple boxes deeper for stronger movement, in detail the three axes with the green rate of change, and the logger's valid data in red. Time outside the person's study window is gray. Added here: the story marks, the session bars and the place band, which stands in for the viewer's map.
- Moves
- The team's graph: each move at its time of day and its length on a log scale, a circle sized by its strength, red to yellow by study day.
- Stories
- Added here. Each labeled story as 30 minutes of readings around its time.
- All the bags
- Added here. A bar from a bag's first story to its last. Bags are this page's reading of the team's labels: a new bag where the size changes, where a story opens one, or after a story that finished one.
The instruments
- Sensor pack
- TJ's logger: a touch controller wired to six copper plates, a three-axis accelerometer, a clock and a memory card, on a lithium cell, in a white plastic case. It wrote a row on any change, about eight a second while moving and one every 10 seconds otherwise. Plate 1 to 6 follow the wiring, and nothing records where each plate sat on a bag.
- GPS
- A receiver to carry everywhere, a fix every five seconds when it had one. Only codes appear here: at home, elsewhere, in transit. Home is the place with the most dwell between midnight and 6 am, a guess tested against the team's labels in the Model view.
- Camera
- A pocket camera, for what the team called stories: talking aloud while eating, at least four asked of each person. None of the videos or pictures is here; the page uses only their times and the team's labels.
- Online study
- A welcome activity and daily check-ins, with “Did you eat [the candy] today?” Only the yes or no is used.
- In-home interviews
- The team visited people at home in June 2011. Pictures and video from six homes survive, and stay out of this page.
- The team's labels
- The team's table answers the same questions for each video story, such as where it took place and how the candy left the bag, with “Unclear” where it could not say. Its in-home guide went back to people for what was missing. These are hand labels, not readings.
What survives, and what stays local
The logger files and GPS tracks of 18 of the 20 kits, the team's viewer and its source, the team's table of labels, and the online study's reports. On this page: moves, touches, place codes and the labels, under codes and by study day. One kit's files have no timestamps, and another's folder is empty. Three stories have no time on their label, and one carries a date before the kits went out.
The participants' videos and pictures, the in-home interviews, the GPS tracks themselves, and the kit photographs that show the packaging or the team stay local. Nothing here says which bag the pack was on, how much candy was left, or what anyone bought.
What it can and cannot tell
A move says the pack moved, and a touch says something conductive came near a plate. Neither says eating: people also carried the bag, and handled the pack to charge it. A session is a rule added here, moves and touches with gaps of five minutes or less, holding at least three touches and a move. It describes handling.
The pack had no sense of how much candy was left. Some plates stayed on for hours, and a touch that lasts over a minute is drawn gray and left out of sessions. Eighteen of the 20 kits left usable logs, and 16 of those people have labeled stories. Rows outside each person's study window are left out, as the team's viewer left them out: they include the hours before a kit reached its person.
The team's labels describe what its researchers saw in videos that people chose to make, so they are not a sample of all eating. Heavy and light are the groups the team recruited.
The study was the Iota team's, for a confections client. TJ designed and built the logger, wrote its firmware and built the data viewer: “I designed and built the logger. This was loosely based on the PlaceLab and MITes work. I built the original data visualizer.” Ann Kauth moderated the online study.