|Methodology||Sampling design||Advantages||Problems and difficulties||application|
|Snowball||K stages||Useful for pilot survey||
Choice of initial list|
The probability of inclusion is unknown
Full network connectivity assumption
Interuniversity survey on “Foreigner Immigration to Italy”
|Respondent driven sampling||Each municipality was divided into four areas, and one eligible immigrant was selected in each of them. First respondents in each area were not allowed to know each other to avoid overlapping networks; and each respondent could provide up to three contacts for other immigrants who had never lived in the same household as the respondent. The procedure was repeated until the final number of questionnaires was achieved.||over-representation of men, especially in the age group 30-39||
Romanian Communities in Spain, 2008. Four municipalities in the region of Madrid. (Sandu, 2009)
|Residential units method (unità abitative)||
List of apartments with at least a foreigner (1° level unit); random selection of one foreigner (2° level units).
The initial list is updated through snowball question.
|Lower non-response rate||
Not suitable in big cities|
High attrition rate (snowball component)
Casacchia & Strozza (1990)
Natale & Strozza (1997)
Quotas by age and gender in 4 Italian Regions.|
Selection channels: from contacts obtained in Senegal, or public spaces, migrant associations, snowballing, interviewers’ contacts
Multiple steps with high sample attrition and (non-random) selection|
selection biases at origin
ITA & SPA (partial sample)|
Beauchemin & González-Ferrer (2011)
3 regions with largest percentages of the targeted population|
Districts where more than 10% of the population belonged to the target population
To select the final respondents, random routes were combined with a spatial sampling method (see below)a
|age distribution and the average length of stay of the surveyed population was quite similar to the Padrón distribution||women were seriously under-represented in most origin groups||
Remittances of Latin-American immigrants in Spain 2012. Adult immigrants from six Latin American countries
(Izaguirre Vizcaya, et al., 2016).
|Spatial sampling (and random routes)||Sampling in centres of aggregation: immigration information offices, public spaces in neighbourhoods and, above all, the queue outside the Moroccan consulate||refusal rates were low – especially among the individuals who were queuing for long hours outside the consulate premises||often the inability to locate anyone in certain public spaces required changing the intersection points||
(Morales & Ros, 2013).
|Centre sampling technique||
List of centre of aggregation (1° level unit); casual selection of one foreign (2° level units).
Non response rate due only to refusal|
Suitable also to big cities
Sample more representative and with weighted probabilities
Target population “present population”|
Use a shorter questionnaire
Lombardy Regional survey every year since 2001
South survey aimed at studying effects of the 2003 regularization (Blangiardo & Farina, 2006)
Integrometro survey aimed at gathering information on the integration process (Cesareo & Blangiardo, 2009).
PER.La survey, to analyze the working trajectories of the migrant population (Ismu, Censis and Iprs, 2010).
Italian sample in the “Push and Pull factors” (Birindelli, et al., 2000) in the Italian, Portuguese, and Hungarian samples of the “Immigrant Citizens Survey” (Huddleston & Tjaden, 2012); in the sample of Milan for the Localmultidem survey (Morales & Pilati, 2014).