Inside SCORM: How It Actually Works (and Why It Matters)

From ZIP files to JavaScript handshakes, a deeper look at the technology that shaped modern eLearning.

Originally Posted on Substack

SCORM has a certain magic to how it works. An SCORM file can be crafted halfway across the world and still seamlessly be uploaded to a corporate LMS, launch without issues, and report back that the learner completed it.

SCORM is a quiet and meticulous handshake between content and system. One that, despite its age, still governs the bones of modern digital learning.

But how does SCORM actually work? And why does it matter?

The Invisible Zip File: SCORM Packaging

In the simplest terms, SCORM begins with a ZIP file. Inside the file lies the entire world of SCORM learning. HTML pages, media files, scripts, and most importantly, a file called imsmanifest.xml.

This is SCORM’s secret map. It lets the LMS know what is actually inside the package and how it’s organized. The IMS Content Packaging specification gave SCORM its blueprint for this.

When LxD professionals upload an SCORM package, the LMS reads the manifest and builds the course structure automatically. We don’t have to do any coding or manual setup. It does it all for us.

The Quiet Conversation: Run-Time Communication

Once the learner clicks “Start” on the LMS, it starts the course and quietly provides a piece of JavaScript, the SCORM API.

Now the content needs to find that API (usually living in the parent browser frame) and let the LMS know that it’s awake and ready. In technical terms, this is the Initialize() function.

From there, a conversation unfolds:

• The content might GetValue retrieve the learner’s name.

• It might SetValue update the learner’s progress.

• It can record scores, completion status, and even question responses.

  
  

All of this happens inside a strict data model defined by SCORM: a set of fields like cmi.core.lesson_status (Did they complete?) and cmi.core.score.raw (What did they score?).

When the learner finishes or closes the course, the content calls Terminate(), signaling the end of the session. The LMS saves the data, updates its records, and reports back to the learning administrator with a clean, concise summary.

SCORM 1.2 vs. SCORM 2004: Small Changes, Big Impact

If you’ve ever wondered why two SCORM courses behave differently, you’re not imagining things. SCORM 1.2 and SCORM 2004 handle some pieces differently.

• SCORM 1.2 is simpler. One SCO (reusable chunks of training that are assembled into organizations within a manifest), one conversation. Completion and pass/fail are conflated.

• SCORM 2004 introduces sequencing rules for how learners move through multiple SCOs. It separates “completion” (Did you finish?) from “success” (Did you pass?).

  
  

SCORM 2004 also added better bookmarking and cleaner resumption behaviors. But its complexity meant that many LMSs and content developers stayed happily married to 1.2. Because simplicity, after all, is a feature.

Why This Rigid Dance Still Matters

In the modern era, where we have mobile apps and AI-driven personalization, SCORM can feel outdated. And in some ways it is. It was built during a time when browser windows were all we had.

Yes, precisely because SCORM is simple, this ensures that a course that is made in Seattle can still work all the way in Singapore. It makes sure that content from multiple vendors can work within the same LMS. It reinforces reliability.

Without SCORM, every LMS would need custom integrations for each piece of content, which would be a nightmare.

The Limits We Inherited

Of course, SCORM does box us in to tracking only basic data. We can’t track informal learning or where those learners go outside the LMS.

Newer standards like xAPI and cmi5 were created to solve these limitations and to free learning data from the browser window.

But understanding how SCORM works remains important. It’s still the foundation of digital learning worldwide.

And for all its age, there’s something admirable about a handshake that still holds after twenty years.

Next in the series: SCORM 1.2 vs. SCORM 2004: A Quiet Family Feud