The IAP2 Spectrum of Public Participation has guided engagement practice since its launch in 1998. Developed by Marty Rozelle, Lewis Michaelson and Doug Sarno, it has shaped how practitioners and decision-makers involve communities in public decisions for nearly three decades. The original team deliberately presented the model as a spectrum rather than a ladder, reflecting the view that the appropriate level of participation depends on the decision being made — not that Empower is always the goal. Now it is undergoing its first major international review — and the proposed changes are significant. While individual IAP2 regions have periodically adapted or interpreted the Spectrum for their own contexts — including IAP2 Canada's 2017 update — this is the first coordinated international review of the Spectrum itself.
This guide summarises the IAP2 Spectrum Evolution project: why it is happening, the four proposed changes, and what they mean for day-to-day practice. We will keep this page updated as the review progresses.
Because the Spectrum underpins training, procurement, policy, engagement plans and reporting across much of the world, even relatively small changes have the potential to influence how thousands of practitioners design and communicate public participation.
Why the Spectrum Is Being Reviewed
The engagement landscape has changed enormously since 1998 — digital participation, changing legislation, rising community expectations, and now AI in everyday practice. IAP2 International launched the Spectrum Evolution project to test one question: is the Spectrum still fit for purpose, and can it be made better for the future?
The project is led by an international project team supported by a globally representative Sensemaking Committee. IAP2 International's 2026 project update highlights the contributions of Dr Tracey Ehl, Luis Oré, Dr Cassie Hemphill and Tiffany Skomro during the current phase of the review. IAP2 Australasia has also identified Marion Short, Chris Cannon and Anne Pattillo as part of the project team.
The Process So Far
Mid-2024: confidential interviews with 24 leading practitioners across every IAP2 region
August–November 2024: regional engagement — more than 1,800 instances of participation through workshops, conference sessions and surveys
February–March 2025: global survey testing proposed changes — 547 responses across five languages
2026: final international consultation on the proposed evolutions, with the survey closing 22 June 2026
The Four Proposed Changes
1. A purpose statement alongside the Spectrum
The Spectrum graphic is often used out of context — as a maturity model, a scorecard, or a target where “Empower” is treated as the goal. A purpose statement would clarify what the Spectrum is for: matching the level of participation to the decision at hand, not ranking engagement quality.
2. Clearer descriptions of each level
Practitioner feedback consistently identified ambiguity in how the levels are described — particularly the boundary between Consult and Involve. Refined descriptions aim to make each level's promise to the public unmistakable.
3. Combining Consult and Involve
The most debated proposal. The Sensemaking Committee suggested testing an option that combines Consult and Involve to clarify the promise each level makes. Many practitioners argue that organisations sometimes describe engagement as “Involve” when, in practice, it operates more like “Consult”. This perceived gap between intent and delivery became one of the drivers for exploring whether the distinction should be reconsidered. Supporters argue that combining the levels could encourage clearer conversations about the influence being offered, while critics worry it could remove a useful distinction between different participation commitments.
4. Repositioning Inform to underpin every level
Rather than sitting as the first column of the Spectrum, Inform would be recognised as foundational to all participation. Every engagement process depends on timely, accurate, accessible information — you cannot meaningfully consult, involve or collaborate with a community that has not been properly informed.
What This Means for Practitioners
Whatever the final outcome, the direction of the review reinforces something we write about often: the Spectrum is a set of promises, not preferences. Each level is a commitment to communities about the role they will genuinely play in a decision. The proposed changes — especially the purpose statement and the Consult/Involve question — are fundamentally about making those commitments more explicit and defensible.
For a deeper look at choosing an engagement level your constraints can actually support, see A Promise, Not a Preference. For the fundamentals, start with What Is Community Engagement?
What Happens Next
The final international survey closed on 22 June 2026. IAP2 International will now consolidate the feedback and determine which proposals are adopted. We will update this guide as outcomes are announced.
Primary sources: the IAP2 Australasia Spectrum Evolution page, IAP2 International, and The Participation Company's account of the Spectrum's origins.