Reconstructing baseline data for impact evaluation and results measurement

This paper, written by Michael Bamberger for the World Bank, analyses why baseline studies are not always conducted and then outlines strategies that can be used to reconstruct baseline data later in the program cycle. 

"Baseline data can come from the project’s monitoring and evaluation (M&E) system, rapid assessment studies, surveys commissioned at the start and end of the project, or from secondary data sources. Whatever the source, the availability of appropriate baseline data is always critical for performance evaluation, as it is impossible to measure changes without reliable data on the situation before the intervention began. Despite the importance of collecting good baseline data, there are a number of reasons why they are frequently not collected, and the purpose of this paper is to present a range of strategies that can be used for “reconstructing” baseline data when they are not available.

The strategies for reconstructing baseline data apply to both discrete projects and broader programs (the term “interventions” is used here to cover both), although they must sometimes be adapted to the special characteristics of each. Projects often introduce new M&E systems customized to the project’s specific data needs, but often with significant start-up delays, which can be problematic for collecting baseline data. In contrast, ongoing programs can often build on existing M&E and other data collection systems as well as have access to secondary data and sampling frames, although these systems are often not sufficient for the purposes of evaluation and tend to be difficult to change. Nongovernmental organizations (NGOs), important development players in many countries, may face different issues with respect to baseline data for their activities." (Bamberger, 2010)


  • Baseline Data Are Important for Assessing Project/Program Results and Impacts
  • Limited Access to Baseline Data in Many Projects/Programs
  • Data for Results Monitoring and Evaluation
  • Strategies for Reconstructing Baseline Data
    • Timing of the baseline
    • Using secondary data to reconstruct the baseline
    • Using administrative data from the intervention
    • Recall
    • Key informants
    • Group interview techniques for reconstructing baseline data
  • Applying the Reconstruction Strategies to Fill In Baseline Data for the RBME
  • Applying Baseline Reconstruction Strategies for Evaluating Outcomes and Impacts
  • Special Issues: Reconstructing Baseline Data for Comparison Groups
  • Operational Implications
  • Implications for National Planning Agencies 


Bamberger, M., (2010). Reconstructing Baseline Data for Impact Evaluation and Results Measurement, The World Bank. Retrieved from: