Intervention Design and Prototyping: Building Evidence-Based Solutions

Learn to select and adapt evidence-based interventions, integrate behavioral theory, create rapid prototypes, conduct user testing, and finalize implementation-ready intervention plans.

Intervention Design and Prototyping: Building Evidence-Based Solutions

You've assessed needs, designed with empathy, and built a logic model. Now it's time to design the actual intervention—the services, products, or programs that will create change.

This week focuses on building solutions that work: grounded in evidence, informed by theory, and validated through testing.

Selecting Evidence-Based Interventions

Not Starting from Scratch

The best interventions build on what already works. Evidence-Based Interventions (EBIs) have been rigorously tested and shown to produce outcomes in controlled settings.

Benefits of EBIs:

Limitations of EBIs:

Finding Evidence-Based Interventions

Key repositories include:

General Public Health:

Specific Topics:

Evaluating Evidence Strength

Not all "evidence-based" claims are equal:

Strong Evidence:

Moderate Evidence:

Emerging/Promising:

Adaptation vs. Fidelity

The core tension in EBI implementation:

Fidelity: Implementing exactly as designed to preserve effectiveness

Adaptation: Modifying to fit local context and population

The Balance:

Identifying Core Components

Core components typically include:

Adaptable elements typically include:

Integrating Behavioral Theory

Why Theory Matters

Theory explains why interventions work—the mechanisms that connect activities to outcomes. Understanding mechanisms allows for:

Common Behavioral Theories

Health Belief Model: Key constructs: Perceived susceptibility, severity, benefits, barriers, cues to action, self-efficacy

"If Maria believes she's at risk for diabetes (susceptibility), that diabetes is serious (severity), that prevention works (benefits), that she can overcome barriers (self-efficacy), and receives a trigger to act (cue), she'll participate in prevention."

Social Cognitive Theory: Key constructs: Self-efficacy, outcome expectations, observational learning, behavioral capability, environment

"If Maria sees people like her succeeding at diabetes prevention (modeling), believes she can do it (self-efficacy), and has the skills and environment to support change (capability + environment), she'll adopt healthy behaviors."

Transtheoretical Model (Stages of Change): Stages: Precontemplation, contemplation, preparation, action, maintenance

"Maria might be in contemplation stage—thinking about change but not ready to act. Intervention strategies should match her stage (increase motivation) rather than assume she's ready for action (provide skills training)."

Mapping Theory to Components

For each program component, identify:

| Component | Theory | Construct Targeted | Mechanism | |-----------|--------|-------------------|-----------| | Peer educator delivery | Social Cognitive | Observational learning | "People like me succeed" | | Skills practice activities | Social Cognitive | Self-efficacy | Mastery experience | | Family involvement | Social Cognitive | Environment | Social support | | Goal-setting worksheets | Health Belief | Self-efficacy | Behavioral planning |

This mapping ensures program components have theoretical justification.

Rapid Prototyping

From Abstract to Concrete

Rapid prototyping creates tangible representations of interventions quickly and cheaply. The goal isn't perfection—it's learning.

Prototype Purpose:

Types of Prototypes

Paper Prototypes:

Role-Play Prototypes:

Service Blueprints:

Minimum Viable Product (MVP):

Prototype Principles

Low-fidelity first: Start rough, refine later

Test early, test often: Don't wait for perfection

Embrace failure: Prototypes are meant to reveal problems

Example: Prototyping a Diabetes Prevention Class

Paper Prototype:

Role-Play Prototype:

Service Blueprint:

MVP:

User Testing and Feedback Loops

"Think Aloud" Testing

Users interact with prototypes while narrating their thoughts:

Instructions:

"I'm going to show you a draft of our program materials. Please tell me what you're thinking as you look at them—what makes sense, what's confusing, what you like, what concerns you. There are no wrong answers."

What to Listen For:

The Feedback Grid

Organize feedback into four categories:

| Likes (What worked) | Criticisms (What didn't work) | |---------------------|------------------------------| | "I like that it shows people like me" | "The times don't work for my schedule" | | "The language is clear" | "Too much reading" |

| Questions (What's unclear) | Ideas (What could be better) | |---------------------------|------------------------------| | "How long is each session?" | "Could we do this online?" | | "What if I miss a class?" | "Add recipes we could try" |

Prioritizing Feedback

Not all feedback is equal. Prioritize based on:

Frequency: Do multiple users raise the same issue?

Severity: Does this prevent use entirely or just reduce satisfaction?

Alignment: Does this feedback align with other evidence?

Feasibility: Can we address this within constraints?

Iteration Cycles

After testing:

  1. Synthesize feedback
  2. Identify priority changes
  3. Modify prototype
  4. Test again

Repeat until:

Finalizing the Intervention Plan

Documentation Requirements

The final intervention plan includes:

Scope and Sequence:

Delivery Specifications:

Materials and Resources:

Quality Assurance:

Alignment Verification

Before finalizing, verify alignment:

The Implementation Blueprint

The finalized plan serves as the blueprint for:

Next week: Taking this blueprint into Agile implementation.

Continue Your Learning

This article is part of an 8-week course on Adaptive Program Planning in the Digital Age. Learn systems thinking, AI-augmented assessment, Human-Centered Design, and Agile implementation for modern public health practice.

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