What exactly are “baseline” and “endline” surveys in the world of global development?
A baseline survey is a study that is done at the beginning of a project to collect information on the status of a subject (anything from crop yields to birth weights) before any type of intervention can affect it.
An endline survey, on the other hand, is the study – often referred to as an impact evaluation – conducted after the end of that intervention. The results of the endline survey are measured against some comparative data – ideally the baseline survey.
What is it so important to perform baseline and endline surveys?
Properly estimating the impact of your intervention requires conducting a baseline survey as a benchmark against which the results of your endline survey can be compared.
Baseline studies also help us determine the priority areas of projects with multiple objectives. Capturing the right information before your intervention begins can show you which aspects of your target population best align to which objectives. In fact, baseline and endline surveys are sometimes required by funding organizations or partners in order to ensure the optimal use of their resources.
Often, the tools used in conducting the baseline and endline surveys are the same as those used in the interventions themselves. This means that these surveys can actually be built into your digital tool, saving you both time and resources.
Five tips for conducting baseline and endline surveys
Conducting baseline and endline surveys is not as simple as asking the same set of questions before and after a project begins. Here are five tips from our experience working on over 500 projects over the years:
Conduct baselines right before your intervention: A baseline survey should be conducted right before the intervention begins. The idea is to provide as little room as possible for variables outside of your control to affect your subject. So, if you allow a significant amount of time to elapse between the baseline and the beginning of the project, you may end up wrongly attributing some changes to the effect of your intervention.
Survey the same population: If the objective of conducting a baseline and an endline is to compare the two to estimate the impact of your project, you need to survey the same subjects before and after. You cannot conduct a baseline of people with one characteristic and an endline of people with another and then deduce a change. You need your baseline survey to act almost as a control group in a traditional scientific study, where the only measurable change between them and the subject of your endline survey is the effect of your intervention.
Iterate and reiterate: While developing your tools for the baseline and endline (e.g. a questionnaire), brainstorm all the different ways a question can be asked, as well as any possible responses. In global development, when we are so often working across populations and languages, this preparedness becomes so much more important, because meanings and lengths of questions and answers can vary widely. Consult our content design considerations as you develop your surveys.
Consider the length of your survey: Sometimes, in a desire to capture every single possible variable, a survey can end up becoming so long that respondents stop before they have completed it. To avoid this, it can be helpful to discuss with the team whether it is possible to capture certain variables though other tools or methods, such as focus group discussions, individual interviews, or through observational data. Upon the completion of your project, you can then evaluate the impact of your intervention across multiple sets of data.
Test your surveys: It is always very insightful to perform usability tests on your survey with a few respondents in the field before actually conducting your baseline survey. This will test the respondents’ comprehension of your questions as well as the time it takes to answer them all. We once used a Likert scale format (a scale from Strongly Disagree to Strongly Agree) for a survey we were conducting verbally. After testing, we realized the format was much more appropriate for self-administered surveys, so we updated those particular questions before conducting the final baseline survey.
As a bonus piece of advice: Be ethical. Always aim to receive the respondents’ informed consent before they take a study. Give them the option to opt out. And if they do participate, ensure they understand the reason for the study, who you are, and how their data will be used.
There is a lot that goes into properly conducting both baseline and endline surveys, from scheduling to audience selection and survey design. Taking these considerations into account will help you design better surveys, giving you cleaner data, and a more accurate measurement of the impact of your intervention. For more advice on survey design, check out our guide on how to design mobile surveys.