Pre-testing, or testing a tool or process before officially starting data collection, should be done before piloting and can be expert- or respondent-driven. Pre-testing is an important way to identify problem questions or sections and reduce measurement error and participant burden. This involves administering the survey to a small subset of participants (either experts or respondents from the target population) and gathering feedback from the participants either indirectly through observation or directly through individual or group debriefing. If it is feasible, consider cognitive interviewing to ensure that question guides (qualitative) or survey items (quantitative) are asking what they intend to ask.1
Piloting should be conducted after pre-testing. Piloting generally involves conducting data collection activities exactly as you will during implementation; however, data collection strategies or instruments may be adapted based on piloting and data from the pilot phase are not used for analyses. Be sure to build time into your workplan to accommodate revisions to the tools and questionnaires after the piloting process. If changes to the data collection tools or strategies are substantial, consider a second pilot of the tools.
1 Ruel, E., Wagner, W., & Gillespie, B. (2016). The practice of survey research. SAGE Publications, Inc,. https://doi.org/10.4135/9781483391700