Snowballing is a simple process of expanding the zone of contacts through initial contacts. The process begins by identifying an initial group of data stakeholders, hopefully those who are already involved in the preliminary stages of the process. These actors or participants are then asked to identify those individuals whom they feel should be involved in the data discovery process as well. This is the “first-order” zone. The researcher then proceeds to contact those actors (whether individuals or groups) and proceeds to have these “second-order” actors, further identify others who they think would have an interest in the project or process (Wasserman and Faust, 1994: 34; see also Goldenberg, 1992; Babbie, 1998; Doreian and Woodward, 1992).

Suggested Plan for Using Snowballing to Identify Data Sources for Analytical Policy Analysis

1. Define the Scope and Criteria

  • Clearly articulate the policy question and the types of data sources needed (e.g., administrative records, survey data, expert reports, grey literature).
  • Set inclusion and exclusion criteria for what constitutes a relevant data source, considering factors such as data quality, accessibility, and relevance to the policy issue[3][5].

2. Identify Initial “Seed” Sources

  • Start with a small set of known, high-quality data sources or experts in the policy area-these are your “seeds”[5][8].
  • These may include foundational reports, key datasets, or recognized experts and organizations relevant to the policy topic.

3. Conduct Initial Outreach and Data Mapping

  • Review the reference lists, bibliographies, and acknowledgments of the seed sources to identify additional data sources (backward snowballing).
  • Contact the authors, data custodians, or experts associated with the seed sources to ask for recommendations of other relevant data sources or contacts (forward snowballing)[5][8].

4. Expand the Network Iteratively

  • For each newly identified data source or expert, repeat the process: review their references and seek further recommendations.
  • Continue this iterative process in multiple “waves” until new referrals yield little or no new information (saturation point)[2][8].
  • Track relationships and connections between sources to identify clusters or gaps in coverage[8].

5. Document and Assess Sources

  • Maintain a detailed log of all identified sources, how they were found, and their relevance to the policy analysis.
  • Regularly assess the quality, credibility, and diversity of the sources being identified to ensure a comprehensive and balanced data set[5][8].

6. Ethical Considerations

  • Ensure that all outreach respects privacy and consent, especially if contacting individuals or using unpublished data[1][4][8].
  • Clearly explain the purpose of the inquiry and obtain permission before sharing contact details or unpublished information.

7. Review and Finalize

  • Once saturation is reached and no significant new sources are emerging, review the full set of identified data sources.
  • Assess for completeness, diversity, and potential biases, and supplement with targeted searches if necessary.

This structured snowballing approach leverages expert networks and reference chains to systematically uncover both well-known and obscure data sources, providing a robust foundation for analytical policy analysis[5][8].

Sources [1] Snowball Sampling - Division of Research and Innovation https://research.oregonstate.edu/ori/irb/policies-and-guidance-investigators/guidance/snowball-sampling [2] What Is Snowball Sampling? | Definition & Examples - Scribbr https://www.scribbr.com/methodology/snowball-sampling/ [3] Snowball Sampling: How to Do It and Pros & Cons - InnovateMR https://www.innovatemr.com/insights/snowball-sampling-how-to-do-it-and-pros-and-cons/ [4] Guidelines for Investigators Using Snowball Sampling Recruitment … https://www.boisestate.edu/research-compliance/irb/guidance/guidelines-for-investigators-using-snowball-sampling-recruitment-methods/ [5] Snowball sampling - Wikipedia https://en.wikipedia.org/wiki/Snowball_sampling [6] [PDF] Snowball Research Strategies https://sru.soc.surrey.ac.uk/SRU33.PDF [7] Snowball Sampling: Explanation, Examples, Pros, and Cons - Dovetail https://dovetail.com/research/snowball-sampling/ [8] What Is Snowball Sampling: 6 Simple Steps With Examples https://surveysparrow.com/blog/snowball-sampling/ [9] Snowball Sampling Method: Techniques & Examples https://www.simplypsychology.org/snowball-sampling.html [10] Snowball Sampling: Introduction - Johnson - Wiley Online Library https://onlinelibrary.wiley.com/doi/abs/10.1002/9781118445112.stat05720