5 Common Theory of Change Pitfalls (And How to Avoid Them)

A Theory of Change (ToC) should be one of the most useful tools in a development practitioner's toolkit. When done well, it clarifies thinking, guides programme design, and provides a foundation for meaningful evaluation. When done poorly, it becomes an expensive wall decoration—a diagram that looks impressive but doesn't actually inform decisions.

After reviewing hundreds of ToCs across the development sector, we've identified five patterns that consistently undermine their usefulness. Here's what goes wrong and how to fix it.

Common patterns in weak theories of change
[Illustration 1: Theory of Change pitfalls]
Recognising these patterns is the first step to building better ToCs
Pitfall 1

The "Everything Leads to Everything" Problem

The ToC diagram has arrows pointing in every direction. Every activity connects to every outcome. The visual looks comprehensive but is actually meaningless—it doesn't help you understand which pathways matter most or where to focus resources.

❌ Weak
Diagram shows 15 activities all connecting to 8 outcomes with 40+ arrows creating a web of connections
✓ Strong
Clear primary pathway from activities → outputs → outcomes → impact, with secondary pathways explicitly marked
The Fix

Identify your main causal pathway first. Make it the spine of your ToC. Then ask: which additional connections are essential to understanding how change happens? Add only those. If everything connects to everything, nothing is clarified.

Pitfall 2

Missing or Magical Assumptions

The arrows in the ToC represent leaps of faith rather than tested logic. Training happens → behaviour changes. Seeds distributed → yields increase. The mechanisms that connect cause to effect are invisible or unexplained.

❌ Weak
"Training farmers" → "Improved agricultural practices"
✓ Strong
"Training farmers" → [Assumption: farmers have access to required inputs; content is contextually relevant; power dynamics allow women to apply learning] → "Improved agricultural practices"
The Fix

For every arrow in your ToC, ask: under what conditions does this connection actually hold? Write down those conditions as explicit assumptions. Then assess which assumptions are already validated by evidence and which are untested hopes.

Pitfall 3

Confusing Activities with Outcomes

The ToC is filled with things the organisation does rather than changes in the world. "Conduct 50 training sessions" is an activity. "Train 500 farmers" is an output. Neither tells us whether anything actually changed.

❌ Weak
"Distribute 10,000 bed nets" listed as an outcome
✓ Strong
"Increased consistent use of bed nets by children under 5" as outcome; "10,000 nets distributed" as output
The Fix

Apply the "so what?" test. For each box in your ToC, ask "so what?" If the answer describes something your organisation does, it's an activity or output. Keep asking until you reach actual changes in knowledge, attitudes, behaviours, conditions, or systems.

Pitfall 4

The "Build It and They Will Come" Fallacy

The ToC assumes that creating something automatically means people will use it and benefit from it. A health facility is built, so health improves. A mobile app is developed, so farmers access information. The adoption pathway is invisible.

❌ Weak
"Build water points" → "Improved water access" → "Better health outcomes"
✓ Strong
"Build water points" → "Communities aware of water points" → "Consistent use of safe water" → "Reduced waterborne illness" (with maintenance and social norms addressed)
The Fix

Map the adoption pathway explicitly. From creation to awareness to access to uptake to sustained use to quality use. At each stage, ask: what could prevent people from moving to the next stage? What will we do about it?

Building a living Theory of Change
[Illustration 2: A living Theory of Change]
A Theory of Change should evolve as you learn
Pitfall 5

The Frozen ToC

The ToC was created during proposal development, laminated for display, and never touched again. It doesn't reflect what the organisation has learned about what works, what doesn't, or how the context has changed.

❌ Weak
Same ToC used for 5 years despite significant programme pivots and evaluation findings
✓ Strong
ToC reviewed annually with documented changes based on monitoring data, evaluation findings, and contextual shifts
The Fix

Schedule regular ToC review sessions at programme milestones. Ask: what have we learned that challenges our assumptions? What pathways are working better or worse than expected? Update the ToC and document why changes were made.

"A theory of change is not a document to be filed. It's a hypothesis to be tested."

A Self-Assessment Checklist

Before finalising your ToC, run through these questions:

ToC Quality Check

Can you identify a clear primary causal pathway from activities to impact?
Are your key assumptions explicitly stated and testable?
Does every "outcome" represent actual change (not just activities or outputs)?
Is the adoption/uptake pathway visible for your key interventions?
When was your ToC last updated based on evidence?

Moving Forward

A good Theory of Change isn't about creating a perfect diagram. It's about forcing yourself to think clearly about how change happens and being honest about what you don't know. It should make your thinking visible so it can be examined, tested, and improved.

If your ToC is doing its job, it should occasionally tell you uncomfortable things: that a favourite activity isn't contributing to outcomes, that a key assumption is failing, that the pathway to impact is longer than you hoped. That's not a failure—that's learning.

ImpactMojo's Theory of Change course and interactive builder are designed to help you work through these challenges systematically. Because every practitioner deserves tools that actually help them think more clearly about creating change.