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MicroSim Verb Explorer

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Learning Objective

Choose the right xAPI verb for each kind of MicroSim interaction — Start/Pause buttons, parameter sliders, clicked Mermaid nodes, hovered Chart.js points, selected vis-network nodes, vis-timeline events, Plotly zooms, and hot-zone clicks on interactive infographic overlays — using a tight set of just eight verbs that still supports mastery assessment.

  • Bloom Level: Understand (L2)
  • Bloom Verb: Recall, Explain, Choose
  • Library: Mermaid

How to Use

The diagram on the left groups the eight recommended verbs into three roles. Click any node to populate the side panel:

  • Cluster nodes (Session, Engagement, Mastery) show the role's design rationale and which verbs belong to it.
  • Verb leaves (e.g., interacted, answered) show the full IRI, a one-line definition, when to emit it, the MicroSim types that typically emit it, and a complete example xAPI statement you can copy.

Hover any node for a one-line tooltip.

The Three Clusters

Cluster Verbs Purpose
Session launched, initialized, terminated Bracket the MicroSim session for duration and lifecycle analytics.
Engagement experienced, interacted Capture viewing and control changes — the workhorses of MicroSim instrumentation.
Mastery answered, completed, passed Turn an exploratory sim into an assessable learning object.

MicroSim Type → Verb Cheat Sheet

A quick guide to which verbs each MicroSim type usually emits:

MicroSim Type Typical Verbs
p5.js simulation with Start/Pause buttons initialized, interacted (Start/Pause/sliders), terminated, completed if goal-driven
Mermaid with clickable nodes initialized, interacted (node clicks), experienced if any node is auto-revealed
Chart.js with hover tooltips initialized, interacted (hover/click), experienced (chart rendered)
vis-network initialized, interacted (node/edge selection), completed if all nodes explored
vis-timeline initialized, interacted (event clicks, range pans), experienced (range visible)
Plotly.js initialized, interacted (zoom, select, legend toggle)
Interactive infographic overlay with hot zones initialized, experienced (hot zone in viewport), interacted (hot zone clicked), answered if "name this region", completed if all regions visited

Why Only Eight Verbs?

Verb sprawl is a real problem. The ADL Verb Registry has dozens of verbs, and custom verbs proliferate fast. Most analytics consumers only care about a small core, and adding more verbs makes pattern detection harder, not easier.

This curated set deliberately leaves out:

  • attempted — overkill for sims that aren't quizzes; interacted covers the "the learner started doing something" signal for exploratory sims.
  • failed / scored — folded into passed with result.success: false for sim-as-assessment cases. scored is for per-item grading inside a quiz, which most MicroSims don't do.
  • progressed — most MicroSims are short enough that completed suffices. Bring progressed back only for multi-stage sims with meaningful milestones.
  • abandoned — emitted server-side when an initialized session times out with no terminated. Not something a MicroSim author writes.

Many p5.js MicroSims have "Start Simulation" and "Pause Simulation" buttons. Both should emit interacted, not launched or initialized:

// On Start button click
xapi.send({
  verb: { id: "http://adlnet.gov/expapi/verbs/interacted",
          display: { "en-US": "interacted" } },
  object: {
    id: "https://textbook.example.org/sims/projectile-motion#start-button",
    definition: { type: "http://adlnet.gov/expapi/activities/interaction" }
  },
  result: { extensions: { "https://example.org/x/control": "start" } }
});

The extensions.control value ("start", "pause", "reset") lets analytics distinguish button presses without inventing new verbs.

Lesson Plan

  1. Read the three cluster overviews in order to understand the design.
  2. Open the seven MicroSim types listed in the cheat sheet above and identify their controls.
  3. For each control type (button, slider, hovered chart point, hot zone), predict aloud which verb you would emit.
  4. Click the verb leaves to check your predictions and inspect the example statements.
  5. Sketch the verb sequence for one of your own MicroSims, from initialized through terminated. Which mastery verb (if any) does it justify?

References