Gagné's Task Analysis Model

Sequencing organizes content from simple to complex. But sequencing alone is not enough. A teacher whose lessons are well-sequenced can still produce students who fail because the underlying learning hierarchy was incomplete.

The story behind the model and a detailed subtraction example show how task analysis works.

The story behind task analysis

Robert Gagné was a teacher and educational researcher. Recounts his experience that led to the task analysis model.

Gagné taught a unit. His instruction was thoughtful. The lessons were well-sequenced. Students performed well during the unit: they completed in-class work, answered questions correctly, and seemed to understand.

Then came the examination. Most students failed.

Gagné did not blame the students. He reflected on his own teaching, looking for what he had missed. He realized that his sequence was logical (one topic followed another in order), but the learning hierarchy was missing. The students had been moving through topics without the underlying skills to actually master each one.

The fix was to map out the entire hierarchy: terminal objectives at the top, intermediate objectives in the middle, basic skills at the bottom. Every step had to be checked. Without the basic skills, even a well-sequenced lesson failed because students lacked the foundation.

This model became known as Gagné’s task analysis model.

A teacher facing student failure should not blame students. They should reflect, like Gagné did, on whether their instruction had a hidden gap. Often the gap is in the learning hierarchy, not in the visible sequence.

Three levels of objectives

Gagné’s task analysis identifies three levels of objectives plus a foundation of basic skills.

Terminal objective. The final ability the unit aims for. Example: “Students will be able to subtract whole numbers of any size.”

Near-terminal objectives. Objectives close to the final ability but with their own prerequisites. Example for the subtraction unit: “Students will subtract numbers across columns with zeros.” This is close to the terminal but specific.

Intermediate objectives. Smaller skills that build toward the terminal objective. Examples: “Students will subtract two-digit numbers without borrowing.” “Students will subtract with borrowing in adjacent columns.”

Basic skills. The foundation the entire hierarchy rests on. Examples: “Students understand the concept of subtraction.” “Students know simple subtraction facts (e.g., 7 - 3 = 4).”

A teacher writing a unit plan must identify all four levels. Without the terminal objective, the unit has no destination. Without basic skills explicitly listed, the unit risks teaching above students’ foundations.

A detailed subtraction example

Here is a complete task analysis for a unit on subtraction. The unit’s terminal objective is “students will subtract whole numbers of any size”.

A teacher might be tempted to plan the unit as a simple sequence:

1. Subtraction in simple columns.
2. Subtraction when zero is involved.
3. Subtraction of one-digit numbers with zero involved.
4. Subtraction when single borrowing is required.
5. Subtraction across columns.
6. Subtraction across columns with zeros.
7. Subtraction of any size.

This sequence looks good. Each step is more complex than the previous. The class moves through the steps in order.

But Gagné’s task analysis adds layers below this sequence. Each step in the sequence depends on more basic skills.

Foundation level (basic skills):

1. Understanding the concept of subtraction. A child who does not know what subtraction means cannot subtract written numbers. The child must understand that subtraction is taking away.
2. Simple subtraction fact knowledge. The child must know that 7 - 3 = 4 and similar small subtraction facts.

Intermediate level (built on basic skills):

3. Subtraction in simple columns. With basic understanding and facts, the child can subtract a one-digit number from a one-digit number written in column form.
4. Subtraction when zero is involved. The child must understand that subtracting zero leaves the number unchanged. This is a separate concept that builds on the basic understanding.

Higher level:

5. Concept of borrowing. Before any borrowing problem, the child must understand what borrowing means and why it is needed. This is a concept (a what) and an application (when to apply it).
6. Subtraction with single borrowing. With the borrowing concept, the child can handle problems requiring borrowing.

Near-terminal level:

7. Subtraction with multiple borrowings.
8. Subtraction across columns.
9. Subtraction across columns with zeros (the most complex case).

Terminal level:

10. Subtract whole numbers of any size.

The total chart has 11 nodes (basic skills, intermediate objectives, near-terminal objectives, terminal objective). Each node has clear dependencies on the nodes below it.

Why a chart helps

A task analysis is best drawn as a chart, with the terminal objective at the top, intermediate objectives below, and basic skills at the bottom. Lines show dependencies.

The chart for the subtraction unit might look like:

 [Subtract whole numbers of any size] (terminal)
 |
 [Subtract across columns with zeros] (near-terminal)
 / \
[Subtract across columns] [Subtract with borrowing]
 | |
[Subtract with single borrow] [Concept of borrowing]
 | |
 [Subtract in simple columns]
 |
[Subtract when zero involved] [Simple subtraction facts]
 | |
 [Concept of subtraction]
 |
 (basic skills)

The chart makes dependencies visible. A teacher can see at a glance which lower nodes a particular upper node depends on. If a student is struggling at “Subtract with single borrow”, the teacher checks the lower nodes. Does the student understand the concept of borrowing? Do they have the simple subtraction facts? The chart points at where to intervene.

Without the chart, the teacher only sees the visible sequence. They may see the student fail and not know which underlying skill is missing.

Flashcard

Why does Gagné recommend drawing task analysis as a chart with dependencies, rather than just listing topics in order?

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Answer

The chart makes prerequisites visible

A simple list shows the sequence but hides what each step depends on.

A chart shows that each upper node depends on lower nodes. When a student fails at an upper node, the teacher checks the lower nodes for the missing skill.

Without the chart, the teacher sees the failure but not its cause.

The lesson from Gagné’s experience

Lesson 1: Reflect on failure, do not blame students. Gagné did not say his students were not smart enough. He looked at his own teaching. A teacher whose students fail should examine the teaching first.

Lesson 2: Sequence is necessary but not sufficient. A well-sequenced unit can still fail if the underlying hierarchy is incomplete. Sequencing arranges visible topics; task analysis maps the invisible prerequisites.

Lesson 3: Map the hierarchy before teaching. A teacher who maps the task analysis before the unit knows exactly what students need. Diagnostic assessment can check each prerequisite. Students who lack a prerequisite get remediation before the unit advances.

Lesson 4: Use the hierarchy when students struggle. A student failing at an upper node tells you something. The hierarchy says which lower nodes to check. Targeted remediation works better than vague encouragement to “try harder”.

Flashcard

What does Gagné's task analysis model add to a well-sequenced lesson?

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Answer

Visible mapping of prerequisites

A sequenced lesson moves through topics in order.

Task analysis adds the invisible prerequisites: basic skills, intermediate objectives, near-terminal objectives, terminal objective.

Sequencing alone can hide gaps. Task analysis exposes them.