Nevertheless, gathering thorough quantitative and qualitative evidence to comprehensively diagnose the shortcomings in the state’s efforts has the potential to become unwieldy and too demanding on advocates and activists. The application of OPERA in practice has raised questions about how to balance comprehensiveness and selectiveness; to take into account a multiplicity of factors, yet be focused and workable. Essentially, finding an appropriate emphasis will depend on the advocacy objective of a particular monitoring activity. The constraints preventing policy implementation vary from case to case. A particular lesson learned in applying OPERA has been the need to set clear parameters in the research design, to avoid overextending the assessment and losing a narrative thread. In Guatemala, for example, this meant honing in on tax policy as the thematic focus running through the study. But in other scenarios the thematic focus might be corruption, political repression, environmental fragility, transition post-conflict, or any other of a host of issues. Another centrally important issue when considering the practicality of OPERA is who is using it, the subject of analysis and the target of advocacy. Different communities of practice reflect distinct theoretical bases and underlying assumptions on how change works, which, in turn, inspires different strategies and entry points for advocacy, be they legal, political, administrative or economic. For this reason, a grassroots group conducting participatory action research to lobby a local authority would use OPERA differently than a national human rights institution auditing a state’s performance to report to a UN treaty body. Experts using econometric methods to advise policymakers on reform in a particular sector likewise would adopt OPERA in a very different manner than litigants presenting evidence of a systemic social or economic rights violation in domestic court. The contexts, targets and objectives of monitoring can differ drastically. In response, OPERA was developed as an agile, adaptable and flexible framework which can be employed by different theories of change and the communities of practice which embody them. This in turn raises challenges in terms of keeping the tools it uses rigorous, yet at the same time accessible and user-friendly. On the one hand, OPERA should be adapted, used and eventually owned by community groups themselves to ensure the monitoring process is accurate, legitimate, serves the interests of those whose rights are at stake, and ideally becomes in time a more permanent feature of the local advocacy terrain. A central role for rights-holders should be a guiding principle of OPERA’s application. On the other hand, OPERA seeks to provide a certain level of conclusiveness across different communities and constituencies so that it may be practically relevant for courts, treaty bodies and policy-makers. Nevertheless, the ability to interchange simple and complex tools at each step enables the framework to stay flexible in this regard, so that it may be used in a participatory manner. It also allows it to evolve as new, more advanced tools are developed and become more accessible down the track. In this respect, the application of OPERA in practice has illustrated both the benefits and challenges of interdisciplinary collaboration. While working across disciplines of law, economics, anthropology, statistics and other social sciences can undoubtedly enrich the quality of analysis, the different conceptual foundations and underlying assumptions of each discipline need to be mutually understood for them to be truly effective. Experience has also illustrated the importance of meaningfully translating the concepts of rights, indicators, benchmarks etc. into the local vernacular, as well as validating research methods and findings with those affected in order to ensure they meet their priorities, objectives and needs. Finally, further thought needs to be given to how adaptable OPERA might be when rights are fulfilled in a less centralized ‘state-centric’ context. In other words, what if it were to be used in a context where Assessing compliance with the obligation to fulfill economic, social and cultural rights 31