Experimental Kit: Stage 1

Planning and Design

Stage 1: Planning & Design

The first stage of an experiment is to identify the primary research question and to design the trial framework.

This foundational phase is where the scientific and administrative roadmap for the study is created. It involves moving from an initial idea to a concrete plan that specifies who the intervention is for, what it aims to achieve, and how its impact will be measured rigorously.

Research Question

Defining a research question is the critical first step for facilitating good research. Research questions should be relevant, clearly formulated, and prioritised based on their potential to inform theory, policy and practice.

To ensure clarity, experimenters often use the PICO framework, which defines the Population, Intervention, Control and Outcomes.

While a study may have secondary objectives, it should focus on a single primary question to guide the study design and sample size estimates. This stage ensures you are asking a question that an RCT is actually equipped to answer – specifically, questions about impact, causality, and “what works”.

Trial Design

A trial design specifies the overall structure of the experiment, including the trial type, randomisation method, and planned analytical approach. A robust design is essential to identify practical requirements and ensure the trial has sufficient statistical power – the ability to answer the research question(s) – based on calculated sample sizes. It also defines whether the study is exploratory (testing under ideal conditions) or pragmatic (testing in real-world settings).

Pre-Implementation Preparation

Before collecting data, it is important to complete all essential administrative and scientific planning. A range of practical steps is necessary to ensure trial integrity and transparency. These might include obtaining ethical approval from an institutional review board (IRB), registering the experiment in a public database to prevent reporting bias, and developing a detailed trial protocol.

Theory of Change

A key framework for this stage is the theory of change and logic model. These tools spell out the underlying rationale of the intervention by mapping how specific activities are expected to lead to primary and secondary outcomes. Developing this logic helps researchers identify the right indicators to measure and ensures the experiment is testing a clear causal chain.