Snowball Sampling vs. Respondent Driven Sampling in Regional Research. Comparing the use of the Methods to Study Migrants Working in Elderly Care

Sabina Kubiciel-Lodzińska


The aim of the article is to compare the effectiveness of the snowball sampling and Respondent Driven Sampling (RDS) for research on migrants working in elderly care. Analyses are based on results of in-depth semi-structured individual interviews conducted among 42 migrants working as caregivers in the Opole region (Poland). This group can be considered as a “hidden population” because, due to the work they provide in the household, frequently illegally, they often demonstrate a strong desire to remain invisible. The methods were compared in terms of: (1) duration of the survey, (2) diversity of the sample, (3) difficulty in applying both sampling methods. In the conducted survey, snowball sampling made it possible to find and reach the required number of respondents faster than the RDS. Both groups differed in terms of gender (more men were recruited by snowball sampling), legality of employment (there were fewer lawfully employed in the RDS group) and average length of stay in Poland (migrants recruited by snowball sampling stayed in Poland for an average of 3.3 years and enrolled by RDS for 1.7 year). In both groups, recruitment was not self-driven by the chain of social networks of respondents. The reason was, inter alia, the structure of the social network of the migrant, which only to a small extent covered other migrants employed in senior care. The article closes the research gap for comparative research using snowball sampling and RDS on the same hard-to-reach population. The survey also attempts to verify to what extent face-to-face RDS can be used to survey hidden and rare populations scattered over a larger area than a city or agglomeration. Therefore the RDS method has been used to recruit respondents from the whole region without limiting the scope to one city or agglomeration.

Słowa kluczowe: elderly carers, migrants, snowball sampling, hard-to-survey population, Respondent Driven Sampling, labour market
Abbasi-Kangevari, M., Amin, K., & Kolahi, A. A. (2020). Antenatal care utilisation among Syrian refugees in Tehran: A respondent driven sampling method. Women and Birth, 33(2), E117-E121. doi:10.1016/j.wombi.2019.02.001
Adedeji, A. (2019). Accessing Sub-Saharan African migrant group for public health interventions, promotion, and research: the 5-wave-approach. Comparative Migration Studies, 7(1), 1–13.
Agadjanian, V., & Zotova, N. (2012). Sampling and surveying hard-to-reach populations for demographic research: A study of female labor migrants in Moscow, Russia. Demographic Research, 26, 131–150.
Atkinson, R., & Flint, J. (2001). Accessing hidden and hard-to-reach populations: Snowball research strategies. Social research update, 33(1), 1–4.
Bagheri, A., & Saadati, M. (2019). Respondent Driven Sampling Population Proportion Estimators. Malaysian Journal of Mathematical Sciences, 13, 101–113.
Bauermeister, J. A., Zimmerman, M. A., Johns, M. M., Glowacki, P., Stoddard, S., & Volz, E. (2012). Innovative recruitment using online networks: lessons learned from an online study of alcohol and other drug use utilizing a web-based, respondent-driven sampling (webRDS) strategy. Journal of Studies on Alcohol and Drugs, 73(5), 834–838.
Bengtsson, L., Lu, X., Nguyen, Q. C., Camitz, M., Le Hoang, N., Nguyen, T. A., ... Thorson, A. (2012).
Implementation of web-based respondent-driven sampling among men who have sex with men in Vietnam. PloS one, 7(11).
Bettio, F., Simonazzi, A., & Villa, P. (2006). Change in care regimes and female migration: the ‘care drain’ in the Mediterranean. Journal of European Social Policy, 16(3), 271–285. doi:10.1177/0958928706065598
Biernacki, P., & Waldorf, D. (1981). Snowball sampling: Problems and techniques of chain referral sampling. Sociological methods & research, 10(2), 141–163.
Bilsborrow, R. E., & CEPAR. (2006). The living conditions of refugees, asylumseekers and other Colombians in Ecuador: Millennium development indicators and coping behavior. In: Ecuador Country Report, Netherlands Interdisciplinary Demographic Institute.
Bonevski, B., Randell, M., Paul, C., Chapman, K., Twyman, L., Bryant, J., ... Hughes, C. (2014). Reaching the hard-to-reach: a systematic review of strategies for improving health and medical research with socially disadvantaged groups. BMC medical research methodology, 14(1), 42.
Broadhead, R. S., Volkanevsky, V. L., Rydanova, T., Ryabkova, M., Borch, C., Van Hulst, Y., Heckathorn, D. D. (2006). Peer-driven HIV interventions for drug injectors in Russia: First year impact results of a field experiment. International Journal of Drug Policy, 17(5), 379–392.
Browne, K. (2005). Snowball sampling: using social networks to research non‐heterosexual women. International journal of social research methodology, 8(1), 47–60.
Brzozowski J., Pędziwiatr K. (2014), Analysis of the integration process of immigrants in Lesser Poland, in: Immigrants in Lesser Poland between integration, assimilation, separation and marginalisation, E. Pindel (ed.), Crakow, 117–240.
Carrillo, S. A., Rivera, A. V., & Braunstein, S. L. (2020). Implementing Respondent-Driven Sampling to Recruit Women Who Exchange Sex in New York City: Factors Associated with Recruitment and Lessons Learned. Aids and Behavior, 24(2), 580–591. doi:10.1007/s10461-019-02485-w
Cohen, N., & Arieli, T. (2011). Field research in conflict environments: Methodological challenges and snowball sampling. Journal of Peace Research, 48(4), 423–435.
Coleman, J. S. (1958). Relational analysis: the study of social organizations with survey methods. Human organization, 17(4), 28–36.
Crawford, F. W., Wu, J. C., & Heimer, R. (2018). Hidden Population Size Estimation From Respondent-Driven Sampling: A Network Approach. Journal of the American Statistical Association, 113(522), 755–766. doi:10.1080/01621459.2017.1285775
Da Roit, B. (2014). Privately paid care for older people in Italy: testing the equivalence between macroregions. Quality & Quantity, 48(2), 577–591.
Da Roit, B., & Weicht, B. (2013). Migrant care work and care, migration and employment regimes: A fuzzy-set analysis. Journal of European Social Policy, 23(5), 469–486.
Dankova, H., Bernard, J., & Vasat, P. (2019). Using the Respondent-Driven Sampling Method to Survey Homeless Populations: Basic Principles, Application and Practical Recommendations. Sociologicky Casopis-Czech Sociological Review, 55(2), 189–214. doi:10.13060/00380288
Di Rosa, M., Melchiorre, M. G., Lucchetti, M., & Lamura, G. (2012). The impact of migrant work in the elder care sector: recent trends and empirical evidence in Italy. European Journal of Social Work, 15(1), 9–27.
Dávid, B., & Snijders, T. A. (2002). Estimating the size of the homeless population in Budapest, Hungary. Quality and Quantity, 36(3), 291–303.
Djuve, A. B., Friberg, J. H., Tyldum, G., & Zhang, H. (2015). When poverty meets affluence. Migrants from Romania on the streets of the Scandinavian capitals. Oslo: Fafo.
Ellard-Gray, A., Jeffrey, N. K., Choubak, M., & Crann, S. E. (2015). Finding the hidden participant: Solutions for recruiting hidden, hard-to-reach, and vulnerable populations. International Journal of Qualitative Methods, 14(5), 1609406915621420.
Faugier, J., & Sargeant, M. (1997). Sampling hard to reach populations. Journal of advanced nursing, 26(4), 790–797.
Frank, O., & Snijders, T. (1994). Estimating the size of hidden populations using snowball sampling. Journal of Official Statistics-Stockholm, 10, 53–53.
Friberg, J. H. (2012). The stages of migration. From going abroad to settling down: Post-accession Polish migrant workers in Norway. Journal of Ethnic and Migration Studies, 38(10), 1589–1605.
Friberg, J. H., & Horst, C. (2014). RDS and the Structure of Migrant Populations. In Applying respondent driven sampling to migrant populations: Lessons from the field (pp. 17–26): Springer.
Gallotti, M. (2009). The gender dimension of domestic work in Western Europe: ILO.
Gerdts, C., Jayaweera, R., Munoz, I., Motana, R., Bessenaar, T., & Wesson, P. (2019). Respondent-Driven Sampling: Evaluating a New Method for the Measurement of Informal-Sector Abortion in Soweto, South Africa. Contraception, 100(4), 312–313. doi:10.1016/j.contraception.2019.07.032
Gile, K. J., Johnston, L. G., & Salganik, M. J. (2015). Diagnostics for respondent‐driven sampling. Journal of the Royal Statistical Society: Series A (Statistics in Society), 178(1), 241–269.
Goodman, L. A. (1961). Snowball sampling. The annals of mathematical statistics, 148–170.
Górny, A., Grabowska – Lusińska I., Lesińska M., Okólski M. (2010). Immigration to Poland: Policy, employment, integration. Wydawnictwo Naukowe” Scholar”.
Gorny, A., & Napierała, J. (2016). Comparing the effectiveness of respondent-driven sampling and quota sampling in migration research. International Journal of Social Research Methodology, 19(6), 645–661.
Górny, A., & Torunczyk-Ruiz, S. (2011). Czy można połaczyć ilość z jakością? Możliwości i bariery podejścia ilościowego w badaniach integracji migrantów w Polsce. Studia Migracyjne-Przegląd Polonijny, 37(2 (140)), 41–58.
Granovetter, M. (1976). Network sampling: Some first steps. American journal of sociology, 81(6), 1287–1303.
Groger, L., Mayberry, P. S., & Straker, J. K. (1999). What we didn’t learn because of who would not talk to us. Qualitative Health Research, 9(6), 829–835.
Gyarmathy, V. A., Johnston, L. G., Caplinskiene, I., Caplinskas, S., & Latkin, C. A. (2014). A simulative comparison of respondent driven sampling with incentivized snowball sampling–The “strudel effect”. Drug and alcohol dependence, 135, 71–77.
Hakim, A. J., Badman, S. G., Weikum, D., Amos, A., Willie, B., Narokobi, R., ... Kauntim Mi Tu Study, T. (2020). Considerable distance to reach 90-90-90 targets among female sex workers, men who have sex with men and transgender women in Port Moresby, Papua New Guinea: findings from a cross-sectional respondent-driven sampling survey. Sexually Transmitted Infections, 96(2), 143–150. doi:10.1136/sextrans-2019-053961
Heckathorn, D. D. (1997). Respondent-driven sampling: A new approach to the study of hidden populations. Social Problems, 44(2), 174–199. doi:10.1525/sp.1997.44.2.03x0221m
Heckathorn, D. D. (2011). Comment: Snowball versus respondent-driven sampling. Sociological methodology, 41(1), 355–366.
Heckathorn, D. D., & Jeffri, J. (2001). Finding the beat: Using respondent-driven sampling to study jazz musicians. Poetics, 28(4), 307–329. doi:10.1016/s0304-422x(01)80006-1
Heckathorn, D. D., Semaan, S., Broadhead, R. S., & Hughes, J. J. (2002). Extensions of respondentdriven sampling: a new approach to the study of injection drug users aged 18–25. AIDS and Behavior, 6(1), 55–67.
Heffner, K., Klemens, B., & Solga, B. (2019). Challenges of Regional Development in the Context of Population Ageing. Analysis Based on the Example of Opolskie Voivodeship. Sustainability, 11(19), 5207.
Hendriks, V. M., Blanken, P., Adriaans, N. F. P., & Hartnoll, R. (1992). Snowball sampling: A pilot study on cocaine use: IVO, Instituut voor Verslavingsonderzoek, Erasmus Universiteit Rotterdam.
Hipp, L., Kohler, U., & Leumann, S. (2019). How to Implement Respondent-Driven Sampling in Practice: Insights from Surveying 24-Hour Migrant Home Care Workers. Survey Methods: Insights from the Field, 1–13.
Hochschild, A. R. (2015). Global care chains and emotional surplus value. In Justice, Politics, and the Family (pp. 249–261): Routledge.
Jaroszewicz, M. (2018). Migration froM Ukraine to Poland the trend stabilises. Centre for Eastern Studies, Warsaw.
Johnston, L. G., Chen, Y.-H., Silva-Santisteban, A., & Raymond, H. F. (2013). An empirical examination of respondent driven sampling design effects among HIV risk groups from studies conducted around the world. AIDS and Behavior, 17(6), 2202–2210.
Johnston, L. G., & Sabin, K. (2010). Sampling hard-to-reach populations with respondent driven sampling. Methodological innovations online, 5(2), 38–48.
Johnston, L. G., Sabin, K., Hien, M. T., & Huong, P. T. (2006). Assessment of respondent driven sampling for recruiting female sex workers in two Vietnamese cities: reaching the unseen sex worker. Journal of Urban Health, 83(1), 16–28.
Jones, E. C. (2003). Class-based social networks in regional economic systems. Research in economic anthropology, 22, 3–24.
Kalter, F. (2011). Social capital and the dynamics of temporary labour migration from Poland to Germany. European Sociological Review, 27(5), 555–569.
Kałuża-Kopias, D. (2018). Imigranci w systemie opieki nad osobami starszymi, Rynek Pracy nr 3 (166), 36–45.
Keryk, M. (2010). ‘Caregivers with a heart needed’: The domestic care regime in Poland after 1989 and Ukrainian migrants. Social Policy and Society, 9(3), 431–441.
Khatib, A., Haji, S., Khamis, M., Said, C., Khalid, F., Dahoma, M., . . . McFarland, W. (2017). Reproducibility of respondent-driven sampling (RDS) in repeat surveys of men who have sex with men, Unguja, Zanzibar. AIDS and Behavior, 21(7), 2180–2187.
Kirchherr, J., & Charles, K. (2018). Enhancing the sample diversity of snowball samples: Recommendations from a research project on anti-dam movements in Southeast Asia. PloS one, 13(8).
Krzyżowski, Ł., & Mucha, J. (2012). Opieka społeczna w migranckich sieciach rodzinnych polscy migranci w Islandii i ich starzy rodzice w Polsce. Kultura i Społeczeństwo, 1(56), 191–217.
Kubiciel-Lodzińska, S. (2019). The role of Immigrants in Providing Elderly Care Services for an Ageing Polish Population: Complementary or Substitutionary. Problemy Polityki Społecznej(2), 87–104.
Lattof, S. R. (2018). Collecting data from migrants in Ghana: Lessons learned using respondent-driven sampling. Demographic Research, 38, 1017–1058.
Lerch, M. (2017). International Migration and City Growth. United Nations Department of Economic and Social Affairs Population Division Technical Paper(2017/10).
Liu, M., McCann, M., Lewis-Michl, E., & Hwang, S.-A. (2018). Respondent driven sampling in a biomonitoring study of refugees from Burma in Buffalo, New York who eat Great Lakes fish. International journal of hygiene and environmental health, 221(5), 792–799.
Lutz, H., & Palenga-Möllenbeck, E. (2011). Care, gender and migration: Towards a theory of transnational domestic work migration in Europe. Journal of Contemporary European Studies, 19(3), 349–364.
Magnani, R., Sabin, K., Saidel, T., & Heckathorn, D. (2005). Review of sampling hard-to-reach and hidden populations for HIV surveillance. Aids, 19, S67-S72.
Maj J., 2015, Gender equality policy after the Polish accession to the EU: Transformation or obstinacy?, in: Karolewski I., Sus M. (eds.), The Transformative Power of Europe, 230–250, Nomos.
Maj J., 2017, Gender Equality in the European Union, Nomos.
McCreesh, N., Frost, S., Seeley, J., Katongole, J., Tarsh, M. N., Ndunguse, R., ... Johnston, L. G. (2012). Evaluation of respondent-driven sampling. Epidemiology (Cambridge, Mass.), 23(1), 138.
McGregor, J. (2007). ‘Joining the BBC (British Bottom Cleaners)’: Zimbabwean migrants and the UK care industry. Journal of ethnic and migration studies, 33(5), 801–824.
McKenzie, D. J., & Mistiaen, J. (2007). Surveying migrant households: A comparison of census-based, snowball, and intercept point surveys: The World Bank.
McNamara, R. P. (1994). The times square hustler: male prostitution in New York city: Praeger/Greenwood.
Meyer, I. H., & Wilson, P. A. (2009). Sampling lesbian, gay, and bisexual populations. Journal of Counseling Psychology, 56(1), 23.
Michaels, S., Pineau, V., Reimer, B., Ganesh, N., & Dennis, J. M. (2019). Test of a Hybrid Method of Sampling the LGBT Population: Web Respondent Driven Sampling with Seeds from a Probability Sample. Journal of Official Statistics, 35(4), 731–752. doi:10.2478/jos-2019-0031
Mühlau, P., Kaliszewska, M., & Röder, A. (2011). Polonia in Dublin: Preliminary Report of Survey Findings. Dublin: Trinity College Dublin.
Napierala, J., & Górny, A. (2013). Assessment of effectiveness of RDS sampling method in migration studies. In Themis conference, Examining migration dynamics: Networks and beyond. UK: Oxford.
Oscos-Sanchez, M. A., Flores, B. B., Claeys, L., Liang, Y. Y., Lopez, B., McDaniel, M. D., Winkler, P. (2019). Using Respondent Driven Sampling to Estimate Homicide and Motor Vehicle Crash Risk among Adolescents and Young Adults in a Latino Community. Journal of Adolescent
Health, 64(2), S21-S22. doi:10.1016/j.jadohealth.2018.10.054
Patrick, J. (2013). A Glasgow gang observed: Neil Wilson Publishing.
Platt, L., Luthra, R., & Frere-Smith, T. (2015). Adapting chain referral methods to sample new migrants: Possibilities and limitations. Demographic Research, 33, 665–700.
Qiu, P. Y., Yang, Y., Ma, X., Wu, F., Yuan, P., Liu, Q. L., & Caine, E. (2012). Respondent-driven sampling to recruit in-country migrant workers in China: A methodological assessment. Scandinavian Journal of Public Health, 40(1), 92–101. doi:10.1177/1403494811418276
Raymond, H. F., Wilson, E. C., Packer, T., Ick, T., Lin, J., & McFarland, W. (2019). High and Stable Human Immunodeficiency Virus Prevalence Among Transwomen With Low Income Recruited With Respondent-driven Sampling, San Francisco, 2010–2016. Sexually Transmitted Diseases, 46(2), 118–124. doi:10.1097/olq.0000000000000916
Reichel, D., & Morales, L. (2017). Surveying immigrants without sampling frames–evaluating the success of alternative field methods. Comparative Migration Studies, 5(1), 1.
Rostker, B. D., Hosek, S. D., Winkler, J. D., Asch, B. J., Asch, S. M., Baxter, C., ... Werber, L. (2010). Sexual orientation and US military personnel policy: An update of RAND’s 1993 study.
Salamońska, J., & Czeranowska, O. (2018). How to Research Multiple Migrants? Introducing Webbased Respondent-Driven Sampling Survey. CMR Working Papers, No. 110/168).
Salganik, M. J., & Heckathorn, D. D. (2004). Sampling and estimation in hidden populations using respondent‐driven sampling. Sociological methodology, 34(1), 193–240.
Schonlau, M., Weidmer, B., & Kapteyn, A. (2014). Recruiting an Internet panel using respondentdriven sampling. Journal of Official Statistics, 30(2), 291–310.
Semaan, S. (2010). Time-space sampling and respondent-driven sampling with hard-to-reach populations. Methodological Innovations Online, 5(2), 60–75.
Simic, M., Johnston, L. G., Platt, L., Baros, S., Andjelkovic, V., Novotny, T., & Rhodes, T. (2006). Exploring barriers to ‘respondent driven sampling’in sex worker and drug-injecting sex worker populations in Eastern Europe. Journal of urban health, 83(1), 6–15.
Sobiesiak-Penszko, P. (2015). Niewidzialna sila robocza: migranci w usługach opiekuńczych nad osobami starszymi: Fundacja Instytut Spraw Publicznych.
Szweda-Lewandowska, Z., & Kałuża-Kopias, D. (2019). Demand for the Labor of Foreign Caregivers from the Perspective of Two Generations: The Elderly and Their Family Caregivers. Przedsiębiorczość i Zarządzanie, 20(3, cz. 1 Współczesne problemy społeczne i ekonomiczne-próba oceny i pomiaru), 79–93.
Taarup-Esbensen, J. (2017). Doing Social science in regions of conflict:–Snowball sampling in Armenia–Snowball sampling in Armenia.
TenHouten, W. D. (2017). Site sampling and snowball sampling-methodology for accessing hardto-reach populations. Bulletin of Sociological Methodology/Bulletin de Méthodologie Sociologique, 134(1), 58–61.
Tyldum, G., & Johnston, L. (2014). Applying respondent driven sampling to migrant populations: Lessons from the field: Springer.
Tyldum, G. (2020). Surveying migrant populations with respondent-driven sampling. Experiences from surveys of east-west migration in Europe. International Journal of Social Research Methodology, 1–13.
Van Baelen, L., Plettinckx, E., Antoine, J., & Gremeaux, L. (2020). Prevalence of HCV among people who inject drugs in Brussels-a respondent-driven sampling survey. Harm Reduction Journal, 17(1), 9. doi:10.1186/s12954-020-00358-3
Van Hooren, F. (2010). When families need immigrants: The exceptional position of migrant domestic workers and care assistants in Italian immigration policy. Bulletin of Italian Politics, 2(2), 21–38.
Vanella, P., Heß, M., & Wilke, C. B. (2020). A probabilistic projection of beneficiaries of long-term care insurance in Germany by severity of disability. Quality & Quantity, 1–32.
Vogt, W. P. 1999, Dictionary of Statistics and Methodology: A Nontechnical Guide for the Social Sciences, London: Sage
Wang, J., Carlson, R. G., Falck, R. S., Siegal, H. A., Rahman, A., & Li, L. (2005). Respondent-driven sampling to recruit MDMA users: a methodological assessment. Drug and alcohol dependence, 78(2), 147–157.
Waters, J. (2015). Snowball sampling: a cautionary tale involving a study of older drug users. International Journal of Social Research Methodology, 18(4), 367–380.
Watters, J. K., & Biernacki, P. (1989). Targeted sampling: Options for the study of hidden populations. Social problems, 36(4), 416–430.
Weinmann, T., AlZahmi, A., Schneck, A., Charry, J. F. M., Fröschl, G., & Radon, K. (2019). Population-based assessment of health, healthcare utilisation, and specific needs of Syrian migrants in Germany: what is the best sampling method? BMC medical research methodology, 19(1), 1–10.
Wejnert, C., & Heckathorn, D. D. (2008). Web-based network sampling: efficiency and efficacy of respondent-driven sampling for online research. Sociological Methods & Research, 37(1), 105–134.
Yang, X., You, L., Jin, D., Zou, X., Yang, H., & Liu, T. (2020). A community-based cross-sectional study of sleep quality among internal migrant workers in the service industry. Comprehensive Psychiatry, 97, 152154.
Zagórowska, A., & Rostropowicz-Miśko, M. (2016). Proces starzenia się ludności a możliwości kreowania miejsc pracy i nowych kierunków kształcenia na podstawie badania sytuacji osób starszych, których dorosłe dzieci przebywają za granicą. Studia Ekonomiczne, 258, 135–147.

Kwartalnik ukazuje się w sposób ciągły on-line.
Pierwotną wersją czasopisma jest wersja elektroniczna publikowana w internecie.