HSPARC

Observer Mode

Observer Mode plays existing video content while capturing synchronized gamepad input from participants. This enables perception studies, content ratings, and comparative analyses.

When to Use Observer Mode

Use Observer Mode when you want to:

  • Collect viewer responses to pre-recorded content
  • Have multiple participants rate the same video independently
  • Compare observer perceptions to original participant experience
  • Study responses to standardized video stimuli
  • Conduct media perception or content evaluation research

Supported Video Sources

Observer Mode can play:

  • HSPARC recordings — Sessions recorded in Recorder Mode
  • Imported videos — MP4, MOV, AVI, or MKV files from external sources

Importing External Videos

To use videos not recorded in HSPARC:

  1. From the main menu, select Manage Videos > Import
  2. Select your video file from the Study Key or connected storage
  3. Enter a descriptive name for the video
  4. Click Import

The video will be copied to your Study Key and made available in Observer Mode.

Starting an Observer Session

1. Select Observer Mode

From the main menu, select Observer Mode.

2. Choose a Video

Browse available videos:

  • My Recordings — Videos captured in Recorder Mode
  • Imported Videos — External videos you've imported
  • Recently Used — Quick access to recent selections

Select the video you want participants to observe.

3. Configure Session Settings

Setting Description
Session ID Unique identifier for this observation session
Observer ID Identifier for the participant(s) observing
Participants Number of observers (1 or 2)
Input Mapping What each controller axis measures
Show Timer Whether observers see elapsed time

4. Configure Input Mapping

Specify what observers are rating. Common configurations:

Perception Studies:

  • Y-Axis: Perceived emotion of person in video (positive ↔ negative)
  • X-Axis: Perceived arousal/intensity (low ↔ high)

Content Evaluation:

  • Y-Axis: Interest/engagement (interesting ↔ boring)
  • X-Axis: Clarity (confusing ↔ clear)

Empathy Research:

  • Y-Axis: Own emotional response (positive ↔ negative)
  • X-Axis: Similarity to perceived target emotion

5. Calibrate Controllers

  1. Click Calibrate
  2. Have observers move joysticks through full range
  3. Verify visualization responds correctly
  4. Click Confirm

6. Brief Your Observers

Explain the task clearly:

"You'll watch a video while using this controller to rate [what they're rating]. Push the joystick up for [high end] and down for [low end]. Adjust continuously as your perception changes throughout the video."

7. Start Playback

  1. Click Start to begin
  2. Optional countdown (configurable)
  3. Video plays while input is captured

During Playback

Observer View

Observers see:

  • The video content (full screen or windowed, configurable)
  • Optional: Their input trace (can be hidden to avoid bias)
  • Optional: Elapsed time

Researcher View (if using separate displays)

On a secondary monitor, you can view:

  • Observer input traces in real-time
  • Video preview
  • Session status

Playback Controls

Control Function
Space Pause/Resume (if enabled)
Escape End session early

Note: For standardized studies, you may want to disable pause functionality to ensure all observers have the same experience.

Video Playback Options

Configure how videos are presented:

Display Options

Option Description
Full Screen Video fills the entire screen
Windowed Video in a window with visible input trace
Picture-in-Picture Small input visualization overlaid on video

Audio Options

Option Description
Original Audio Play video's audio track
Muted No audio playback
Custom Audio Replace with different audio file

Timing Options

Option Description
Normal Speed Play at original speed (1.0x)
Adjusted Speed Slow down or speed up (0.5x - 2.0x)
Pause Points Auto-pause at specified timestamps

Ending the Session

Automatic End

When the video finishes, data is automatically saved.

Manual End

Press Escape or click End Session to stop early. You'll be asked to confirm:

  • Save partial data — Keep what was recorded
  • Discard — Don't save this session

Post-Session

After completion:

  1. Session summary displays
  2. Add notes about the observation
  3. Click Save & Close

Data Output

Each observer session creates:

ObservationSessionID/
├── input_obs1.csv      # Observer 1 ratings
├── input_obs2.csv      # Observer 2 ratings (if applicable)
├── events.csv          # Event markers
├── metadata.json       # Session config, source video reference
└── source_ref.json     # Link to original video

Comparing to Original

If observing an HSPARC recording, you can directly compare:

  • Original participant input → source_recording/input_p1.csv
  • Observer perception → observation_session/input_obs1.csv

Both files use the same timestamp/frame format for easy alignment.

Multi-Observer Studies

Same Video, Multiple Observers

To collect ratings from many observers on the same video:

  1. Use consistent Session ID prefix (e.g., Video01_Obs001, Video01_Obs002)
  2. Keep input mapping identical across observers
  3. Use Researcher Mode to aggregate and compare

Simultaneous Observers

For two observers watching together:

  1. Select 2 participants in session setup
  2. Each observer uses their own controller
  3. Both input streams are captured simultaneously

Best Practices

Standardization

  • Use identical instructions for all observers
  • Control viewing conditions — Same room, lighting, seating
  • Randomize video order if showing multiple videos
  • Counterbalance conditions across observers

Data Quality

  • Verify engagement — Watch for flat-line input indicating disengagement
  • Check for technical issues — Review a sample of sessions in Researcher Mode
  • Document anomalies — Note any interruptions or issues in session notes

Participant Comfort

  • Explain duration — Let observers know video length before starting
  • Offer breaks for long videos or multiple videos
  • Check controller grip — Ensure comfortable hold for extended sessions

Troubleshooting

Video won't play

  • Verify video format is supported (MP4, MOV, AVI, MKV)
  • Try re-importing the video
  • Check for file corruption

Audio out of sync

  • Re-import video with "Re-encode" option
  • Check original video file for sync issues

Observer can't see video clearly

  • Adjust display settings
  • Check room lighting (reduce glare)
  • Position display at comfortable viewing distance

For more solutions, see Troubleshooting.

Next Steps