# Recordings, Wearers & Templates

There are a number of organizational constructs we use to make working with our tools flexible and reliable:

A recording is made each time you press record in the Invisible Companion app. Each recording has a wearer and a template associated with it. Once uploaded to Pupil Cloud you can add recordings to projects, this creates a context for you to add enrichments to aggregate and analyse your data.

Finally, workspaces are used to keep recordings, wearers, templates, and projects organized and isolated so you can share them with clients and collaborators.

# Recordings

A recording starts and stops when you press the red record button in Pupil Invisible Companion App. While this should feel similar to recording a video, there is a lot more happening behind the scenes. When you are recording with Pupil Invisible Companion App, you are capturing not only video data but several more sensors (see Data Streams).

Recordings are designed to be as robust as possible. If at any point a sensor is disconnected during a recording, it will automatically start capturing again as soon as it is reconnected. You could start a recording with no Pupil Invisible glasses connected and plug them in at a later time. As soon as they are connected, data will be captured.

The Pupil Invisible Companion App has several more features to ensure a robust data collection and will e.g. warn you in case the Companion device's battery is running low or if you run out of storage space.

# Wearers

Wearers are the people wearing your Pupil Invisible glasses. In a typical study, each subject would be a wearer. Every recording you make is assigned to a wearer to help you organize your recordings. You can create new wearers on the fly in the Pupil Invisible Companion App or in advance in Pupil Cloud.

Every wearer is assigned a unique ID, such that you can edit the name and profile picture at any time without mixing up your recordings.

In some cases, it can make sense to use the offset correction feature to compensate for systematic offsets in the predictions of individual wearers. To access this feature click on the name of the currently selected wearer on the home screen and then click "Adjust". The offset you set will be saved in the wearer profile and applied to future recordings of this subject automatically.

# Templates

Templates are used to add meta-data to a recording (e.g. age, gender, or location). They are forms that can be filled out at recording time to document important information for your study. The responses will be saved alongside the recording. Further, templates define a naming scheme for recordings. If, for example, you add a field for the Experiment Name to the form, you can set this value to be added to your recording names automatically. This is useful if you have a pre-defined structure for your study.

# Form for Meta-Data

You can create new templates in Pupil Cloud and customize them to your use case. You can add as many form fields as you want, including text fields and multiple-choice fields.

You can set individual fields of the template to be "required", such that a recording can not be stopped before filling out those fields.

Before your templates become available for selection in the Pupil Invisible Companion app, you need to publish them. After they are published, they can no longer be edited to ensure consistency between responses.

Some example use-cases for template forms include:

  • Questionnaire: During the recording of a scientific study participating subjects are often asked to fill out a questionnaire to capture e.g. demographic data. You can simply create a template for your questionnaire so your subjects can fill out the questionnaire on the Companion Device. All questionnaire answers will be saved alongside the recording data associated with the according wearer.
  • Recording Structure: If your recording schedule has a known structure, e.g. different recording phases or one recording per week, you can set up a template to note down the respective phase or week for each recording.
  • Documenting the unplanned: Data collection does not always go as planned. Sometimes a subject did not quite understand the instructions and sometimes something went wrong in the experiment workflow. Using templates you can immediately note down what happened and flag recordings that will require further inspection. This will be saved as part of the recording, so you do not have to keep a separate list of notes.

# Naming Scheme for Recordings

The only required field when creating a new template is the Recording Name, which determines the naming scheme of your recordings. Any text you type in this field will be included in the recording names. You can add form fields to the Recording Name as well, to include the corresponding values entered at recording time to the recording name. Additionally, you can add the following pre-defined elements to the name:

  • template_name: The name of this template.
  • wearer_name: The name of the current wearer.
  • date: The date of recording. Format YYYY-MM-DD.
  • time: The recording start time. Format HH:mm:ss.
  • uuid: The unique ID of the recording. Format uuidv4.

# Example

The below template definition is an example for a data collection called Museum Study. This collection is happening with several subjects in multiple sessions. We can track which subject a recording was made with using the associated wearer profile. To track what session a recording belongs to, we have a multiple-choice form field in the template.

In the Recording Name field of the template, we defined a naming scheme that conveniently summarizes the recording in the context of this study. It uses a mix of custom text (the gray "chips"), the wearer name, and the multiple-choice form field about the session (which has the form field ID 2255e141). This scheme will create names like Museum Study - Jane - Session 2.