*3.2. Qualitative Data*

#### 3.2.1. Participants

From all the surveyed youth, we selected 10 mentees, their 10 mentors, and 10 nonmentored youths using a *typical case purposive sampling* [66], and carried out thirty semistructured interviews right after completing the T2 surveys. For the selection, we took into account youth who were not outliers in the quantitative outcomes, their ability to express more adequately their feelings and thoughts in Spanish, and their level of engagement with the mentoring experiences. In this sense, we avoided choosing those most and least engaged. For the non-mentored youth (control group), we selected those that expressed some ability to seek some assistance. We also considered similarities between the interviewees of the control group and the mentoring group, for example, their country of origin, age, place of residence, or year of arrival.

#### 3.2.2. Interview Guidelines

For the elaboration of the interview guidelines, we conducted a discussion group with four former unaccompanied minors who had participated in previous editions of the mentoring programme. They helped us to adjust the main topics of the interview to their needs and youth perspective. Mentors and mentees were interviewed individually at different times and spaces by the researchers to provide a space to freely talk about their experiences. The youths were asked about their migration journey, how they reached Barcelona, the types of support they received upon arrival and now, their stressful experiences, how they coped with them, what their aspirations and needs are, and how their mentors or other types of support had helped them in their coming-of-age process.

#### 3.2.3. Analysis

All the interviews were recorded and transcribed. We coded the materials using ATLAST.ti (Scientific Software Development GmbH, Berlin, Germany) following a flexible coding strategy [67], paying attention inductively to the information provided by the interviewees, but also taking into consideration the main categories used in the quantitative fieldwork, such as resilience, youth hope, self-esteem, and educational expectations and needs. The subthemes and codes used are presented in Table 1, as well as quote examples of every code. Other categories were also created based on what young people mentioned, which is why, in the results section, we use some quotes that do not correspond directly with the variables used in the quantitative analysis. However, all of them are related to the study's subthemes (psychological well-being and educational futures). These categories were: *Perceived Support*, *Access to new resources, Loneliness/Isolation,* and *Planning of pathways*.


**Table 1.** Subthemes, codes, and quote examples.
