In practice

REX: the Results and Evidence eXchange

Key messages

Staff and stakeholders of official development assistance (ODA) activities want similar information about what is being delivered, how and why. Yet collecting and analysing data from different programmes and systems is challenging. The United Kingdom’s Results and Evidence eXchange (REX) is a common language for data, acting like a dictionary for computers and enabling users to share and combine data more easily. This supports the comparison and combination of results information across diverse ODA projects.


Using data on the results of development co-operation activities for learning, communication and decision making carries a number of challenges:

  • Trade-offs are needed between standardisation and tailoring. As systems tend to be designed for quantitative data, working with qualitative and longer-form reporting is extremely difficult, while capturing disaggregation is cumbersome. At the same time, rigid results frameworks and standard indicators do not provide for flexibility and adaptation.

  • Aggregation and comparisons are impossible or burdensome. Links between results data and long-term and portfolio outcomes are not captured, while inconsistency among projects is common and data formats are unhelpful.

  • Causality and evidence are often not captured, making the contribution of inputs to results and lessons unclear.

  • Reporting requirements are diverse. The same or similar data often have to be presented in different ways for different audiences or purposes.

The United Kingdom’s Foreign, Commonwealth and Development Office (FCDO) found that a lot of data was trapped in log frames or in Microsoft Word and PowerPoint files. Users had been describing their theories of change, and all of this information was related, but it was difficult to aggregate or combine across portfolios. For some thematic areas, results data systems had become outdated, whereas for others, no digital solution existed at all.


The objective was to develop a common data model that would enable FCDO to translate results data from different tools into a common language for analysis. Through successive workshops over several months and with different thematic teams, FCDO developed a dictionary between digital formats that could describe in a common language the key aspects of results across different areas. Using this dictionary, it then developed a tool for capturing data from portfolio areas identified for the pilot.

Data Interoperability was an important principle in the design of the Results and Evidence eXchange (REX), including interoperability with the data systems of other organisations. Building a tool in-house provided a cheaper solution than contracting externally.

Figure 1. Varying results needs across FCDO stakeholders

Note: HMG = Her Majesty’s Government.

Source: FCDO.


The REX data model and tool have already enabled the collection of results data on the FCDO’s International Climate Finance programme without the use of external proprietary software. This form of collection allows results information to be combined with data from other portfolios to facilitate analysis.

Testing is in progress with other portfolios identified as pilots. Further combinations of data will be tested and available in the coming months.

REX is also adding value by facilitating the management of information, encouraging changes to ways of working and helping staff to understand why it is important to have results data in the first place.

Lessons learnt

  • Establishing clear and specific user needs is essential. To develop tools that are well received, it is essential to spend time consulting staff to establish clear and specific user needs. This must then be balanced with senior leadership and current strategic interests.

  • There is scope to reduce the administrative burden. The approach that was taken, in particular the focus on interoperability, should mean that other Development Assistance Committee (DAC) members can apply this data model in the design of new tools and processes. Data could then be shared easily between partners and other official development assistance providers, reducing the administrative burden on partners and directing more resources to development activities. The code base behind the United Kingdom’s system is independent of the FCDO’s administrative systems, and can be shared with other actors to use as a basis for new tools, or developed further in collaboration.

Further information

This work is a collaboration between the FCDO and the Data Science Campus FCDO Hub team at the Office for National Statistics.

If you are interested in adopting the REX common data language, or collaborating in its development with the FCDO and Office for National Statistics Data Science teams, reach out to Tom Wilkinson, Head of Data Science, Information and Digital Directorate, FCDO, [email protected].

OECD resources

OECD, Results in development co-operation,

OECD, Guiding Principles on Managing for Sustainable Development Results,

To learn more about United Kingdom’s development co-operation see:

OECD (2021), "United Kingdom", in Development Co-operation Profiles, OECD Publishing, Paris,

OECD (2020), OECD Development Co-operation Peer Reviews: United Kingdom 2020, OECD Development Co-operation Peer Reviews, OECD Publishing, Paris,