Two young people looking at a mobile phone in Johannesburg South Africa

Published on 15 January 2024 | Simon Moore, Director of Programmes at Avert

Building on innovative approaches used by researchers at the University of Maastricht to evaluate the Dutch sexual health information website, Sense (ref 1), we are now halfway through a 12-month project seeking to learn, test, and improve our Be in the KNOW sexual health information brand.

We are doing this by comparing the behavioural aims of Be in the KNOW website and social media content with actual user behaviour on those pages and posts, to draw out areas of potential improvement. In later stages we will use user experience and A/B testing to support improvements, and will evaluate the impact of improvements on user behaviour through endline analytics, surveys, and user interviews.

Starting with ABCD

The first phase of the project has been to carry out a theoretical analysis of the behavioural aims of the Be in the KNOW website and social media channels, using the acyclical behaviour change diagram (ABCD) method. We selected two web pages to be representative of wider site content (our ‘vaginal sex’ and ‘when to test for HIV’ pages), and nine social media posts relating to the same topic areas.

The ABCD approach breaks down the intervention – in our case a web page or a social media post – into what is called a ‘causal-structural chain’. Essentially this maps the behaviour change methods (BCM) used in the intervention (for example modelling, persuasive communications, or scenario-based risk information) and how these link through to the ultimate behaviour change you are seeking (for example, testing for HIV, or having enjoyable sex without STIs and unplanned pregnancies) .

The output of this approach is a set of ABCD diagrams which visualise the intended aims of an intervention (see example below). They show how the behaviour change methods are applied in an intervention and how the intervention targets the determinants of behaviour. The approach breaks down all the elements of an intervention to make it clearer what the change objectives and behavioural aims and sub-aims of a communications intervention are, so you can more meaningfully evaluate the difference the intervention is making.

One of the ABCD diagrams
An example of one of the ABCD diagrams

But while the diagrams are useful to document the rigor of the process, the process itself is also useful to aid systematically thinking through the different behavioural components of specific Be in the KNOW content.

To develop and complete the ABCD process we used the Intervention Mapping Taxonomy (ref 2) which brings together learning about what is effective in changing behaviour. The taxonomy is a guide showing what behaviour change methods have been tested and found to be effective to shift particular behavioural determinants (things that influence behaviour).

Through this process we have examined which behaviour change methods Be in the KNOW channels are using, whether these have been correctly applied and could be improved, and whether there are other methods that could be relevant to shift behavioural determinants. We have also reviewed whether all relevant behavioural determinants are addressed through the pages and posts, and whether all sub-aims have been targeted. The process also highlights other aspects of an intervention that are missing or that might reduce its effectiveness.

Why is this relevant?

Avert’s work is underpinned by behaviour change theory and aims, and this process has provided an opportunity to go into a greater level of detail and thinking about how we are using behaviour change approaches across our Be in the KNOW brand. This is particularly valuable for our social media work which has grown organically with less time to systematically analyse where and how we are using behaviour change methods across our posts.

The ABCD process also provides a theoretical grounding for the improvements we make on the site. We see the insights from analysing these initial two pages and social posts being relevant more widely across the rest of the website and social channels.

The process has highlighted things that are missing, areas where we could make improvements, and additional behaviour change methods that would be relevant and useful for us to think about using in future content, page design and functionality. The approach may also provide a theoretical structure for a more detailed evaluation of Be in the KNOW in the future.

Avert’s work is underpinned by behaviour change theory and aims, and this process has provided an opportunity to go into a greater level of detail and thinking about how we are using behaviour change approaches across our Be in the KNOW brand.

Summary and next steps

The ABCD process has highlighted in detail the key change objectives, determinants and behavioural aims and sub-aims for each webpage and post. It has also highlighted a number of elements and approaches that could be considered in the future to increase the behavioural impact of the Be in the KNOW brand.

As a result of carrying out the ABCD process we have also reflected on how we can incorporate and institutionalise some of the behavioural analysis of this process into new content development and content review processes across our work, with new steps added and operationalised.

The next phase of the project is to compare the behavioural aims of these webpages and social media posts with actual user actions, and then implement improvements based on an analysis of the results. We will evaluate the success of the improvements in supporting achievement of change objectives, shifting behavioural determinants, and supporting intention to act on behavioural aims and sub aims.

Through the project we are aiming to better understand what makes effective health learning journeys online and we will continue to share learning across the sector as the project progresses.

For more information on this project contact Simon Moore, Director of Programmes at Avert.


  1. Metz, G., Roosjen, H., Zweers, W., Crutzen, R., Evaluating use of web-based interventions: an example of a Dutch sexual health intervention, Health Promotion International, Volume 38, Issue 4, August 2023, daab190,

  2. Kok, G., Gottlieb, N. H., Peters, G.-J. Y., Mullen, P. D., Parcel, G. S., Ruiter, R. A. C., Fernández, M. E., Markham, C., & Bartholomew, L. K. (2015). A Taxonomy of Behavior Change Methods; an Intervention Mapping Approach. Health Psychology Review. DOI: 10.1080/17437199.2015.1077155

Photo credit: Gulshan Khan/Avert/Ikusasa Lethu. Photos are used for illustrative purposes. They do not imply health status or behaviour.