Exp-lookit-change-detection Class

Whether to do audio-only (vs also video) recording. Can be overridden by consuming frame.

List of audio types to expect for any audio specified just with a string rather than with a list of src/type objects. If audioTypes is ['typeA', 'typeB'] and an audio source is given as intro, the audio source will be expanded out to [ { src: 'baseDir' + 'typeA/intro.typeA', type: 'audio/typeA' }, { src: 'baseDir' + 'typeB/intro.typeB', type: 'audio/typeB' } ]

Base directory for where to find stimuli. Any image src values that are not full paths will be expanded by prefixing with baseDir + img/. Any audio/video src values provided as strings rather than objects with src and type will be expanded out to baseDir/avtype/[stub].avtype, where the potential avtypes are given by audioTypes and videoTypes. baseDir should include a trailing slash (e.g., http://stimuli.org/myexperiment/); if a value is provided that does not end in a slash, one will be added.

Set to true to display this frame in fullscreen mode, even if the frame type is not always displayed fullscreen. (For instance, you might use this to keep a survey between test trials in fullscreen mode.)

Whether to use the camera in this frame. Consuming frame should set this property to override if needed.

Whether to end any session (multi-frame) recording at the end of this frame.

Function to generate additional properties for this frame (like {"kind": "exp-lookit-text"}) at the time the frame is initialized. Allows behavior of study to depend on what has happened so far (e.g., answers on a form or to previous test trials). Must be a valid Javascript function, returning an object, provided as a string.

Arguments that will be provided are: expData, sequence, child, pastSessions, conditions.

expData, sequence, and conditions are the same data as would be found in the session data shown on the Lookit experimenter interface under 'Individual Responses', except that they will only contain information up to this point in the study.

expData is an object consisting of frameId: frameData pairs; the data associated with a particular frame depends on the frame kind.

sequence is an ordered list of frameIds, corresponding to the keys in expData.

conditions is an object representing the data stored by any randomizer frames; keys are frameIds for randomizer frames and data stored depends on the randomizer used.

child is an object that has the following properties - use child.get(propertyName) to access:

• additionalInformation: String; additional information field from child form
• ageAtBirth: String; child's gestational age at birth in weeks. Possible values are "24" through "39", "na" (not sure or prefer not to answer), "<24" (under 24 weeks), and "40>" (40 or more weeks).
• birthday: Date object
• gender: "f" (female), "m" (male), "o" (other), or "na" (prefer not to answer)
• givenName: String, child's given name/nickname
• id: String, child UUID
• languageList: String, space-separated list of languages child is exposed to (2-letter codes)
• conditionList: String, space-separated list of conditions/characteristics
• of child from registration form, as used in criteria expression, e.g. "autism_spectrum_disorder deaf multiple_birth"

pastSessions is a list of previous response objects for this child and this study, ordered starting from most recent (at index 0 is this session!). Each has properties (access as pastSessions[i].get(propertyName)):

• completed: Boolean, whether they submitted an exit survey
• completedConsentFrame: Boolean, whether they got through at least a consent frame
• conditions: Object representing any conditions assigned by randomizer frames
• createdOn: Date object
• expData: Object consisting of frameId: frameData pairs
• globalEventTimings: list of any events stored outside of individual frames - currently just used for attempts to leave the study early
• sequence: ordered list of frameIds, corresponding to keys in expData
• isPreview: Boolean, whether this is from a preview session (possible in the event this is an experimenter's account)

Example:

function(expData, sequence, child, pastSessions, conditions) {
    return {
       'blocks':
            [
                {
                    'text': 'Name: ' + child.get('givenName')
                },
                {
                    'text': 'Frame number: ' + sequence.length
                },
                {
                    'text': 'N past sessions: ' + pastSessions.length
                }
            ]
      };
  }

(This example is split across lines for readability; when added to JSON it would need to be on one line.)

Maximum recording length in seconds. Can be overridden by consuming frame.

Maximum time allowed for video upload before proceeding, in seconds. Can be overridden by researcher, based on tradeoff between making families wait and losing data.

An object containing values for any parameters (variables) to use in this frame. Any property VALUES in this frame that match any of the property NAMES in parameters will be replaced by the corresponding parameter value. For example, suppose your frame is:

{
   'kind': 'FRAME_KIND',
   'parameters': {
       'FRAME_KIND': 'exp-lookit-text'
   }
}

Then the frame kind will be exp-lookit-text. This may be useful if you need to repeat values for different frame properties, especially if your frame is actually a randomizer or group. You may use parameters nested within objects (at any depth) or within lists.

You can also use selectors to randomly sample from or permute a list defined in parameters. Suppose STIMLIST is defined in parameters, e.g. a list of potential stimuli. Rather than just using STIMLIST as a value in your frames, you can also:

• Select the Nth element (0-indexed) of the value of STIMLIST: (Will cause error if N >= THELIST.length)

   'parameterName': 'STIMLIST#N'

• Select (uniformly) a random element of the value of STIMLIST:

   'parameterName': 'STIMLIST#RAND'

• Set parameterName to a random permutation of the value of STIMLIST:

   'parameterName': 'STIMLIST#PERM'

• Select the next element in a random permutation of the value of STIMLIST, which is used across all substitutions in this randomizer. This allows you, for instance, to provide a list of possible images in your parameterSet, and use a different one each frame with the subset/order randomized per participant. If more STIMLIST#UNIQ parameters than elements of STIMLIST are used, we loop back around to the start of the permutation generated for this randomizer.

   'parameterName': 'STIMLIST#UNIQ'

Function to select which frame index to go to when using the 'next' action on this frame. Allows flexible looping / short-circuiting based on what has happened so far in the study (e.g., once the child answers N questions correctly, move on to next segment). Must be a valid Javascript function, returning a number from 0 through frames.length - 1, provided as a string.

Arguments that will be provided are: frames, frameIndex, expData, sequence, child, pastSessions

frames is an ordered list of frame configurations for this study; each element is an object corresponding directly to a frame you defined in the JSON document for this study (but with any randomizer frames resolved into the particular frames that will be used this time).

frameIndex is the index in frames of the current frame

expData is an object consisting of frameId: frameData pairs; the data associated with a particular frame depends on the frame kind.

sequence is an ordered list of frameIds, corresponding to the keys in expData.

child is an object that has the following properties - use child.get(propertyName) to access:

• additionalInformation: String; additional information field from child form
• ageAtBirth: String; child's gestational age at birth in weeks. Possible values are "24" through "39", "na" (not sure or prefer not to answer), "<24" (under 24 weeks), and "40>" (40 or more weeks).
• birthday: timestamp in format "Mon Apr 10 2017 20:00:00 GMT-0400 (Eastern Daylight Time)"
• gender: "f" (female), "m" (male), "o" (other), or "na" (prefer not to answer)
• givenName: String, child's given name/nickname
• id: String, child UUID

pastSessions is a list of previous response objects for this child and this study, ordered starting from most recent (at index 0 is this session!). Each has properties (access as pastSessions[i].get(propertyName)):

• completed: Boolean, whether they submitted an exit survey
• completedConsentFrame: Boolean, whether they got through at least a consent frame
• conditions: Object representing any conditions assigned by randomizer frames
• createdOn: timestamp in format "Thu Apr 18 2019 12:33:26 GMT-0400 (Eastern Daylight Time)"
• expData: Object consisting of frameId: frameData pairs
• globalEventTimings: list of any events stored outside of individual frames - currently just used for attempts to leave the study early
• sequence: ordered list of frameIds, corresponding to keys in expData

Example that just sends us to the last frame of the study no matter what: `"function(frames, frameIndex, frameData, expData, sequence, child, pastSessions) {return frames.length - 1;}"``

Whether to do audio-only (vs also video) recording for session (multiframe) recording. Only used if starting session recording this frame.

Maximum time allowed for whole-session video upload before proceeding, in seconds. Can be overridden by researcher, based on tradeoff between making families wait and losing data.

Whether to initially show a message saying to wait until recording starts, covering the entire frame. This prevents participants from seeing any stimuli before recording begins. Only used if recording is being started immediately.

Whether to stop media and hide stimuli with a message saying to wait for video upload when stopping recording. Do NOT set this to true if end of recording does not correspond to end of the frame (e.g. during consent or observation frames) since it will hide everything upon stopping the recording!

Whether to start recording ASAP (only applies if doUseCamera). Consuming frame should set to override if needed.

Whether to start a session (multi-frame) recording as soon as possible upon loading this frame. This allows you to conduct video recording across multiple frames, simply specifying which frame to start and end on. Individual frames may also provide frame-specific recording capabilities; it is best NOT to conduct both a multiframe 'session' recording and frame-specific recording simultaneously as multiple video streams will eat up bandwidth. If you decide to use session recording, turn off recording for any frames that would otherwise record. There can be multiple session recordings in an experiment, e.g. from frames 1-3 and 5-10.

List of video types to expect for any audio specified just with a string rather than with a list of src/type objects. If videoTypes is ['typeA', 'typeB'] and a video source is given as intro, the video source will be expanded out to [ { src: 'baseDir' + 'typeA/intro.typeA', type: 'video/typeA' }, { src: 'baseDir' + 'typeB/intro.typeB', type: 'video/typeB' } ]

[Only used if showWaitForRecordingMessage is true] Text to display while waiting for recording to begin.

[Only used if showWaitForRecordingMessage is true] Background color of screen while waiting for recording to begin. See https://developer.mozilla.org/en-US/docs/Web/CSS/color_value for acceptable syntax: can use either color names ('blue', 'red', 'green', etc.), or rgb hex values (e.g. '#800080' - include the '#'). The text on top of this will be either black or white depending on which will have higher contrast.

[Only used if showWaitForUploadMessage is true] Text to display while waiting for recording to begin.

[Only used if showWaitForUploadMessage is true] Background color of screen while waiting for recording to upload. See https://developer.mozilla.org/en-US/docs/Web/CSS/color_value for acceptable syntax: can use either color names ('blue', 'red', 'green', etc.), or rgb hex values (e.g. '#800080' - include the '#'). The text on top of this will be either black or white depending on which will have higher contrast.

[Only used if showWaitForUploadMessage and/or showWaitForRecordingMessage are true] Image to display along with any wait-for-recording or wait-for-upload message. Either waitForWebcamImage or waitForWebcamVideo can be specified. This can be either a full URL ('https://...') or just a filename, which will be assumed to be inside `baseDir/img/ if this frame otherwise supports use of baseDir`.

[Only used if showWaitForUploadMessage and/or showWaitForRecordingMessage are true] Video to display along with any wait-for-recording or wait-for-upload message (looping). Either waitForWebcamImage or waitForWebcamVideo can be specified. This can be either an array of `{'src': 'https://...', 'type': '...'}` objects (e.g. providing both webm and mp4 versions at specified URLS) or a single string relative to `baseDir/<EXT>/` if this frame otherwise supports use of `baseDir`.