Multiple Object Tracking: Follow the Moving Targets

At the start of each round, several objects are surrounded by numbered rings. Those rings provide shape and number cues, so target preview does not rely on color alone. After the preview, all objects use the same border and fill. They move continuously, bounce at the field boundaries, and separate when paths bring them too close.

When the tracking interval ends, every object stops without changing its identity or jumping position. You select exactly the number of original targets shown in the settings. Feedback marks original targets, correct selections, and false selections before the next round begins.

Target selections is the number of submitted choices. Correct targets are original targets selected at the end; false selections are distractors selected in error; missed targets are original targets omitted. A round is exact only when every target is selected and no distractor is selected.

Overall target accuracy equals correct targets divided by correct targets plus false selections plus missed targets. Exact-round rate is exact rounds divided by completed rounds. The difficulty label records the full object, target, speed, duration, and size settings rather than pretending they collapse into a clinical norm.

Adding targets increases the number of identities that must stay distinct. Adding distractors increases competition for space. Higher speed changes positions more quickly, while a longer duration requires tracking identities for more time. Smaller objects and a smaller display can make separation harder to see.

The controls limit total objects to 4–12 and targets to 1–6, always fewer than total objects. Speed, movement duration, object size, and rounds also have bounded values. Change one or two factors at a time if you want to understand why a session changed.

Object positions are stored as normalized coordinates, so resizing the browser preserves the active layout instead of restarting or teleporting the round. The animation measures recent frame intervals. If average frames become unusually slow, the session receives a low-frame-rate validity flag rather than treating rendering difficulty as user performance.

When the tab becomes hidden during movement, the task pauses and records a focus-interruption flag. Resume continues from the current positions. Users who prefer reduced motion receive a warning before starting because movement is the mechanism of this task; a static substitute would not be equivalent.

Visual search presents a field and asks you to locate an item based on its current appearance. Multiple object tracking removes the identifying appearance after preview. You are not searching for a feature; you are maintaining which moving tokens were designated earlier.

This difference matters when reading results. A fast visual search time does not predict a tracking score, and a tracking result should not be described as visual-search speed. Use the tool that matches the action you want to observe.

Keep total objects, targets, speed, duration, object size, browser zoom, display size, and device refresh behavior steady. A 120 Hz desktop display and an older phone may render the same nominal speed differently. Touch target size and viewing distance also affect end-of-round selection.

Review validity flags before comparing history. A session with a hidden tab or low frame rate remains saved because silently discarding inconvenient data would be misleading, but it should not be treated as cleanly comparable.

The browser task does not reproduce the visual demands of a road, sports field, air-traffic display, or laboratory apparatus. It uses simple geometric objects and one bounded motion field. Performance reflects this layout and is sensitive to hardware and rendering conditions.

Do not use the result to judge professional fitness, neurological status, or general attention capacity. It is suitable for learning how tracking tasks work, practice, and repeated personal observation under controlled settings.

Completed sessions save settings, aggregate selection metrics, timestamps, and validity flags in this browser. The moving paths and pointer coordinates are not uploaded. You may clear the tool history from the result panel.

Site visit analytics can still receive ordinary page-use information as described in the privacy policy. That analytics stream is separate from the multiple object tracking score stored in localStorage.