Guidelines on Appropriate Payments to Participants

The projects offered on the Unforgettable marketplace vary and as a consequence so do the payments that researchers offer. There are two basic components to take into account when making an offer.

The first is the work that the participant will need to do. Often researchers will ask participants to complete a survey or experimental procedure. We recommend a payment of US$10 per hour prorated if the task will take more or less time than that. This rate takes into account what is a reasonable amount to pay for the effort that will be required, but also that the data remains the property of the participant. As a consequence, they will be entitled to sell this data again should another researcher want to purchase it.

On other occasions the tasks that participants must do will be spread over many days. For instance, in an ecological momentary assessment task (EMA), a participant may have to respond several times a day. To compensate them for this kind of activity we suggest estimating the amount of time they will take to complete the task and then adding 20% to account for the interruptions.

When setting up a project on the marketplace you will be asked to specify an acceptance condition. The acceptance condition indicates the minimal amount of data that the participant must accumulate in order to qualify for the study. The participant can see this acceptance condition when they are deciding whether to complete the study. If they do not qualify they will not be compensated and any data they do collect will not be available to you. In EMA studies, it is typically the case that people do not complete every microsurvey. So keep this in mind when setting the acceptance condition. It is reasonable to expect a participant to complete 75% of surveys. For instance, if you have a study that asks participants to complete a microsurvey 8 times each day for 5 days you might set the acceptance criterion to 30 completed events.

When considering how much to pay the participant, the payment should cover both the effort of the participant and the nature of the data they are making available to you. For example, if a participant is required to complete an online study and you want access to their GPS data, then you should compensate them for both their time spent completing the study and the GPS data you will access.

Some types of data are more valuable than others because they are rare, sensitive or take additional effort by the participant to collect. For instance, a month worth of mood microsurvey data is more valuable than a month of GPS data because fewer people have collected the mood data and it might require the participant to complete micro surveys several times a day. By contrast the GPS data usually accumulates automatically if a participant has the Unforgettable app installed.

Below we list some suggested payments for different kinds of data. These are intended to provide some general guidance for researchers. However, these payments are at your discretion.

Data type Payment (USD)
Unforgettable App data
  • GPS
  • Accelerometry (collected 8-16 times per second)
  • Obfuscated audio (segments are 500 ms in duration and are stored as Mel Frequency Cepstral Coefficients)
  • Raw Audio (30 second segments)
  • Classified Audio (labels derived using machine learning classifiers on the obfuscated audio e.g. traffic, voice, cafe
  • Images (can be taken from pouch on chest)
  • Weather and Temperature
  • Season
  • Place Types (e.g. restaurant, place of worship, park)
  • Addresses
  • Distance travelled (in each hour period)
  • GPS, audio and images are collected every ten minutes by default although the rate can be changed.
$5 per month
  • metadata plus the raw contents
$7 per month
Phone calls
  • time and obfuscated person only - not contents
$7 per month
  • time and obfuscated person only - not content
$7 per month
Button data
  • Button data (Users can place button icons on their phones. These buttons can be configured to record behaviours and states like "Exercised" or "Stressed". Each press comes with the time and GPS coordinates)
$0.20 per response
Ecological Momentary Assessments $0.50 per microsurvey
Online Survey or Experiment
  • e.g. personality survey
$10 per hour

Example Project Costings

Example 1: Just passive data

When your primary research question focuses on the environment of the participants, passive data from the Unforgettable app may be all you need. Let's suppose you wished to access the GPS, accelerometry and obfuscated audio data from 50 participants for two weeks. You would pay an Unforgettable fee of US$10 per participant. In addition we would recommend offering US$5 to the participants, although this is at your discretion. The total cost would be US$750.

Cost per participant US$ US$
Participant Fee $5.00 $250
Unforgettable Fee $50.00 $2500
Total $2750

Example 2: Passive data plus an experiment/survey

Experience sampling data is very useful when studying human memory as it allows one to establish ground truth in people's lives. In this example, we will calculate the cost of an experiment in which you require the GPS data for two months from 100 participants and then will ask them to engage in a memory experiment during which they will be asked where they were at various times. We will assume that the experiment will take one hour to complete.

Cost per participant US$ US$
Participant Data Fee (2 months) $10.00 $1000
Participant Experiment Fee (1 hour) $10.00 $1000
Unforgettable Fee (2 months) $100.00 $10000
Total $12000

Example 3: Passive data plus ecological momentary assessment plus an experiment/survey

Let's suppose that you are interested in how people's emotional state impacts their ability to make judgements about where they were at a given time. Now you may wish to have participants answer microsurveys 8 times a day to rate their emotions at those times. Typically, these paradigms are only sustainable over a couple of weeks, so we will use that as our collection period. Participants typically will miss some of the surveys, so let's assume that you experience an 80% completion rate. Note one can set a minimum completion rate (say 70%) and any participants who do not achieve that will not be included in the study and you will not be required to pay any fees for them. Again, let's assume you require 100 participants.

Cost per participant US$ US$
Participant Data Fee $5.00 $500
Participant Experiment Fee (1 hour) $10.00 $1000
Participant EMA Fee (14 days * 8 surveys/day * $0.50/survey * 80% completion rate) $44.80 $4480
Unforgettable Fee $50.00 $5000
Total $10980