Pathways to Sustainable Intergenerational Programs: Lessons Learned from Portugal

Despite the fundamental role given to the sustainability of intergenerational programming regarding their demonstrated impact on an aging society, only a few studies have undertaken an exploration of the qualitative core dimensions of sustainable intergenerational programs. This article addresses how the sustainability of educational intergenerational programs relates to why and how intergenerational program managers in the Portuguese area of Porto may have developed different attitudes and beliefs around adequate implementation of the programs. Drawing on qualitative interview data of a four-case fieldwork study conducted in Porto, Portugal, the study examines autonomy, empowerment, and intergenerational relationships as dimensions other than time duration behind program sustainability. Attention to the managers’ narratives on how intergenerational programs are implemented can help to explain why some dimensions are more highlighted than others. A qualitative analysis of intergenerational program sustainability, it is argued, offers considerable findings which provide opportunities to its implementation and intersection with managers’ beliefs. Findings suggest a need to de-emphasize both time duration and managers’ persona as the key for sustainability. We recommend intergenerational program sustainability as an area for future theorizing through providing a conceptualizing framework that might go beyond the normative focus on its duration and into the relational nature of these programs.


Introduction
This article addresses how the sustainability of educational intergenerational programs (IP) relates to why and how IP managers in the Portuguese area of Porto may have developed different attitudes and beliefs around implementation of IP. In the context of this paper, sustainability is not approached at the macrolevel but at the programmatic level, i.e., in the sphere of social program planning and implementation.
By definition [1,2], a non-familial IP pursues a clear intentionality and has a structured design that aims to bring people from different generations together with a beneficial goal in mind. IP can foster opportunities to establish meaningful relationships [3,4] and, therefore, increase both participants' and community's well-being [5,6]. Various other benefits are associated with good quality intergenerational contact as provided in IP [7,8]. In fact, intergenerational programming has experimented a promising growth over the past decades [9,10]. Overall, the appraisal of this development is positive [11] and the associated goods have been recognized widely in the literature [12], especially those to do with older people's well-being and a more successful and active aging process. Now, if we look at how IP are planned and implemented, we may conclude that discussions have been somehow scarce and are stagnated. In terms of their planning, for the most part, IP are approached as any other social program [13]. In this context, the term 'social program' refers to programs that try to meet social needs, more specifically through working around interactions between people, and with an aspiration to get public or social legitimacy [14]. Typically, social programs are based upon a logic model whose standard ingredients are an array of initial resources to be invested and some budgeted activities to be carried out in a given setting according to a schedule leading to a group of outputs and outcomes which, hopefully, shall converge to attain the programs' objectives and goals [15]. Studies about the implementation of IP have covered issues such as partnership building, monitoring, execution barriers, and evaluation [16,17]. Sustainability, however, has barely been addressed [18,19].
The definition of sustainability in the context of social program planning and implementation normally alludes to the "continued ability of an innovation (infrastructure or program) to meet the needs of its stakeholders" [20,21]. Hence, the typical connection between program sustainability and program duration in time (continuity beyond the initial financing) that it is so spread in the literature on social programs [22,23] in general and on IP in particular [24]. Rationales for program sustainability are countless and most probably the only evidence is the lack of a standard approach [25,26].
It is against this non-standardized backdrop that we feel that a stance in the way of an ad hoc conceptual framework should be taken to facilitate progress. Firstly, program sustainability may be considered at different levels, but always with a plural and qualitative rational in mind: plural because sustainability requires a dynamic synergy within and throughout all program stages, and qualitative because sustainability calls for a comprehensive and interpretative approach, rather than merely a measuring exercise. A plural approach to sustainability may promote a better comprehension of the IP as a whole, but also it may pave the way for a critical perspective of the entire process. Moreover, program sustainability entails an active process, not a one-time event. Therefore, reducing the discussion to the binary sustainable versus non-sustainable program represents a superfluous and simplistic approach.
Secondly, we argue that the sustainability of a social program (as it is the case with IP) resides not as much in its continuity as in its demonstrated autonomy, i.e., its capacity to self-navigate at various levels (e.g., management, participation, and securing human and financial resources). Continuity only says that a program is still functioning, but we contend that sustainability precedes and governs continuity. A sustainable program is able, among other capacities, to determine whether its continuity is desirable or not. It is not by chance that empowerment and sustainability have been approached jointly [27]; if stakeholders feel empowered in relation to the program, they will have the capacity to manage how and if the program may continue, hence the program might be deemed sustainable. Actually, in this conceptual context, it may be a good idea to discontinue a program for some time in order to make it more sustainable after future resumption.
Thirdly, and in line with [18], in the particular case of social programs, sustainability has a lot to do with the web of interactions and relationships upon which by definition any social program exists. The sustainability of these relationships and not merely of program activities is a key factor to understand and assess program sustainability. Given the interactive nature of social programs, they will not be sustainable unless an incipient, but promising, set of relationships is in place. The social program autonomy mentioned above has a lot to do as well with these relationships, in which program managers are involved in different ways. Therefore, our conceptual framework of program sustainability puts a strong emphasis on sustaining social relationships.
When it comes to IP in general, some factors that can help ensure sustainability have been considered in the literature, but mainly with the idea of sustainability-as-continuity in mind. For instance, it has been argued that sustainability may be enhanced through using a long-term approach, securing funding, and good monitoring and evaluation [28]; having a champion of intergenerational work; counting on "effective strategic planning, the involvement of partners and the mainstreaming of intergenerational activity" [29] (p. vii); delivering institutionalized outcomes [30]; and working out effective partnerships [17].
Weaver et al. [31] address sustainability as "a common barrier to Intergenerational Practice" (p. 3) and identify a range of critical components to enhance IP sustainability: on-site presence, open communication and positive intergroup contact (based on reciprocity and interdependence) among partners, relationship-building, cross-training, best practice use, and documentation. According to these authors, following the tenets of contact theory may equally help to implement the IP, and the use of principles from community-based participatory action research may foster IP sustainability too. Now, regarding educational IP specifically-i.e., those IP that run in educational settings like schools and with a clear goal around the improvement of educational processes and performance, the specific interest of this paper-their sustainability faces many specific challenges too [11,32]. For instance, [32] described three main difficulties: time, curriculum and teachers' training experience. Firstly, the school calendar is abided by strict organizational times, sometimes incompatible with other institution's calendars or even with the participants' willingness to continue their involvement. Secondly, in school endeavors, the academic curriculum has a central role. Thus, IP (as any other social program unless it has been launched top-down by educational authorities) may struggle to find a lasting way into the school life. Finally, the authors argued, only teachers who "have taken part in related professional development . . . are most likely to be open to new teaching and learning areas" (p. 63). Therefore, professional experience of those managing an IP may count whenever evaluating implementation and sustainability of that IP.
The postulate behind this article is doubled-edged. The analysis of core dimensions for sustainable educational IP according to program managers should be taken further, and program sustainability should be deemed a plural and qualitative process extending beyond mere continuity to include decision-making autonomy by program stakeholders and the existence of effective web relationships. It is argued as well that stronger attention to sustainability of educational IP may bring about a more accurate planning, implementation, and evaluation of these programs. This postulate justifies the need to find appropriate qualitative dimensions of sustainability since the literature only mentions disperse quantitative indicators of educational IP sustainability for empirical research. Using such a plural and qualitative approach would permit organizations to focus on the core dimensions that are needed to manage participants' and managers' expectations for a sustainable program delivery.
Consequently, and drawing on a case study fieldwork conducted in Portugal, a country where educational IP have expanded, this article outlines findings on key dimensions for implementing sustainable educational intergenerational programs in the narratives of the program managers. Ultimately, paying attention to the point of view of IP managers makes sense for it has been argued that planning "effective, sustainable intergenerational programs" is one of the competences required by practitioners in the field [5].

Materials and Methods
This article focuses just on four in-depth case studies within a larger sample of seven cases [33]. Following [34] "duality criterion", four case studies were kept to balance situational grounding and theoretical generality.
Prior to case selection, and in order to identify existing educational IP in Porto, a mapping exercise was carried out in which the main characteristics of these programs were recorded. For more than five years, the first author had been implementing IP in Porto, and a deeper understanding of the intergenerational field was needed. This mapping was aimed at identifying all IP implemented in the Porto area at the time of research. It was developed by identifying all IP being implemented by the municipalities in the Porto area, and through an online consultation of IP planned by elementary and secondary schools. This quest included looking up the websites of 117 elementary schools and 79 secondary schools, as well as the gerontological plans of the 9 municipalities in the area of Porto. Search terms like 'intergenerational program', 'intergenerational project', 'grandparents', 'elderly', and 'grandchildren' were used. Most schools deemed to have in place an IP, however according to [35], intergenerational "demonstration projects" require regular meetings where the participants share activities beneficial for both generations. For that reason, what the schools considered IP were actually intergenerational activities, such as grandparents' day celebrations, seasonal commemorations, or visiting nursery homes. Therefore, the latter criteria were used to select sample cases among the mix of intergenerational activities and to identify actual IP. A mapping protocol based on key concepts related to IP and sustainability assisted us in conducting the data collection in a systematic way (Table A1, Appendix A). At the time of data collection, two of the four cases presented in this paper were still functioning, while the other two had already ended.
The research approach to define an adequate design of qualitative dimensions of sustainability was based on induction and deduction in order to analyze IP managers' narratives ( Figure A1, Appendix A). Deduction takes theory and relates the theory to reality to interpret it and make predictions, whereas induction takes reality and creates theory. This study can be seen as having deductive qualitative dimensions of sustainability as per literature and an inductive approach as dimensions were identified inductively through a thematic analysis of the managers' narratives. In Figure A1 (Appendix A), the blue circles relate to deductive dimensions and the orange circles relate to inductive dimensions. This set of dimensions of sustainability was used to create the themes and questions for interviews. Three different themes, composed by several questions, were identified and tailored to represent managers' perceptions and narratives.
Drawing on qualitative interviews conducted with IP managers, a case-by-case analysis of a sub-sample of four IP selected from a larger study was carried out by the first author [33]. Additionally, [36] postulated that a case-by-case study permits combining theory and empirical data at different stages of the research [37]. Furthermore, pursuing to comprehend in greater detail dimensions of sustainability as interpreted by IP managers naturally lent itself to a case study framework, because case studies seek to study a phenomenon in its context [38]. The case-by-case analysis enabled to highlight the educational context, which in itself is a multigenerational one with demonstrated potential to promote intergenerational relationships. In our purpose to elicit theoretical dimensions about the sustainability of IP, we adopted an exploratory and interpretive case study approach [39]. In an exploratory approach, data collection purports to learn about personal behaviors and choices through the own narratives of the interviewees [39,40]. The interpretative nature of the approach focuses on the wider understanding of meanings attached to a certain phenomenon. A similar approach has already been used in previous intergenerational studies (e.g., [41,42]).
Finally, since we aimed to create an opportunity for dialogues and close collaboration between the researchers and the participants, we initially invited the interviewees to organize freely their own narratives and views on IP. The latter is an especially relevant strategy when the phenomenon under study needs clarification and consistency [43]. This research strategy enabled us to not only reveal if and how IP managers might have implemented different dimensions of sustainability into the course of their programs, but to explain why and how IP managers in the Portuguese area of Porto may have developed different attitudes and beliefs around IP implementation [44].
A heterogeneous and convenient sample was generated according to managers' age, educational trajectory, and professional and training experience (Table A2, Appendix A). Participants were mainly females with ages ranging from 39 to 60 (x = 49) at the time of interview. All participants had a university degree in social or educational sciences, and most worked in monogenerational educational institutions, i.e., institutions that are designed to serve the needs and interest of a single generation, such as schools. The managers' job description did not include any tasks related to intergenerational activities and the managers were not paid for implementing an IP. The IP were equally heterogenous (Table A3, Appendix A). Its length varied from 2 to 12 years. Likewise, the number of participants differed among IP, and it ranged from 70 to 340 participants. The age of young participants in the elementary schools varied between 6 and 9 years, while in the secondary schools they varied between 13 and 15 years. The participants of one of the case studies were university students, aged between 18 and 23 years. Regarding the older participants, the average age was 70 years. Although, two of the case studies had a significant group of participants in their eighties. In all the IP, the staff members and managers were mid-age adults. Therefore, the IP included people from three different generations. As inclusion criteria for interviewees, it was sufficient to be available and to have implemented one of the selected IP. From there, each one of the interviewees was contacted directly or via Skype and the nature of the study was explained. All the participants gave full verbal consent to take part in an interview. Individual semi-structured interviews took place face-to-face at the participants' workplace, except for two interviews that were made via Skype.
Semi-structured interviews require guidelines [45]. With this in mind, we developed an outline that allowed the interviews to flow naturally and to address all issues at stake. Questions in the interviews encouraged interviewees to elaborate on core dimensions of sustainability. We conducted seven interviews in total. The average interview duration was 45 min, although a few interviews exceeded that time.
Data was audio recorded and transcribed in full. An in-depth thematic analysis to explore key dimensions was undertaken. Emphasis was placed upon the subjective perspectives of the IP managers. The main driver during the analysis of the semi-structured interviews was to comprehend the IP managers' viva voce accounts of which dimensions for IP sustainability may facilitate a more thorough planning, implementation, and evaluation of these programs. Data were incorporated into tables to identify key themes across interviewers. An analysis was conducted and a data coding process was initially conducted manually. Upon completion, all interviews were transcribed and coded using the computer package NVivo11 software for qualitative analyses. A deductive-inductive procedure was carried out to identify and organize recurrent themes across the whole data set [46], including themes to do with IP management, implementation and evaluation, sustainability, and good practices. Next, we linked the coding to the main concepts of the study (Table A1, Figure A1, Appendix A). Therefore, the coding process was grounded in the qualitative data, but took key concepts from the literature [34] as well into consideration.

Results
The sample was diverse in its representation of hard-to-reach IP, number of participants, and managers' educational and professional backgrounds. This diversity was achieved through mapping sampling as detailed in the methods section above. Selected IP were developed either in primary and secondary schools or in university contexts. From the authors' point of view, this diversity demonstrated a strength in the qualitative design, indicative of the extensive range of experience on IP management.
In this section, we present the results and our analysis taking each case in turn. We highlight how three interrelated themes emerged as influencing, in various ways and often subtly, the sustainability of these IP: (i) continuity of the IP, (ii) autonomy/empowerment of stakeholders, and (iii) existence of intergenerational relationships. In doing so, we also reflect on how different forms of design, implementation, and evaluation were considered to influence IP sustainability. The analysis of the hierarchy charts (Hierarchy Charts A1, A2, A3, and A4, Appendix A) showed the weight given by each manager to the different dimensions of sustainability. Intergenerational relationships were the core dimension highlighted by all, although other different subcomponents were addressed too. Manager-emphasized participants' needs, decreased stereotypes between generations, and fostered mutual support through the learning experience were the most common subcomponents of intergenerational relationships.
The autonomy and empowerment of stakeholders had a direct correspondence to the dimension of sustainability, named partnerships ( Figure A1, Appendix A). Formal partnerships among community networks and families were strongly indicated by the majority of the managers. This PHGM manager reported that a consultation with an academic is a significant partnership that empowered her IP management.
The coordinator's skills were another dimension of sustainability highlighted by the managers that relates to autonomy, empowerment, and continuity. The continuity of the IP managers was seen as a significant dimension of sustainability by all the interviewees. Furthermore, the most significant subcomponents regarding coordinator's skills included being knowledgeable about different generations (children, youth, and elders) as well as having attended formal training on IP management.
In support of previous research, this study found that IP not only are relational social projects, but that the various relationships fostered and enriched during an IP (relationships among participants and relationships between multidisciplinary teams and between institutions) are the core dimensions to make it sustainable.

Case Study One-PA
PA had its origin in a partnership between the city council and the University of Porto in 2003/04 and it was still in place at the time of interview. PA emerged from a clear intention of the city council to implement projects that could bring generations together. The city council came across various social challenges, such as the social isolation and loneliness pervading a specific area of Porto's historic city center, where many elderly people lived. Furthermore, a large number of university students who arrived each year in Porto to attend college were facing challenges in finding accommodation. The purpose of PA was not to exclude stakeholders, but rather to work jointly with them to improve IP sustainability. Although at the time of the interview this IP had been in place for 12 years, according to its manager, PA's sustainability was not rooted in its continuity. According to the data analysis, the sustainability dimensions highlighted by the PA's manager were: partnerships, participants needs, intergenerational relations, co-design, and coordinator's skills (Hierarchy Chart A1, Appendix A).
Giving the participants the choice to self-navigate and strengthen their relationships through additional meetings, it can be argued, was not clearly recognized as sustainable. Therefore, sustainability depended on the relationships established among the participants, the local stakeholders, and between participants' networks (e.g., neighbors and friends). PA started with a formal partnership; however, sustainability was built upon activation of community networks with the participation of local institutions. The stronger bonds between partners' organizations had been reaffirmed along the implementation of this IP bringing about an autonomous and sustainable institutional relationship. The PA's manager commented on the program's institutional relationships in the following way: I think this was one of the main goals and priorities: the need to create situations, projects with people of different ages and to promote relationships between generations . . . . Initially, we had as informal partners local institutions that are closely linked with the older population. Since then, every year we promote meetings with those partners to raise awareness and to support us in spreading the program to those who need it most. . . . The program has spread to other areas. Since its start, PA had other requests from older people who also wanted to participate in the program. Here the word of mouth was very important and other people who do not live in the historical zone began to participate in PA.
[PA manager] Older citizens in Porto had claimed more interactions with younger people and stated the loneliness felt by the lack of social connections. PA's manager asked for support to local institutions that would know far better participants' needs and consequently would be able to attract more participants to the IP. At this point, this manager approached sustainability as laid on a growing number of participants: PA main partnership is FAP which has a very important role in publicizing the program to the students and in raising awareness of the program. Their staff conducted focus groups and induction meetings for the students to decide whether or not this is the type of project they are looking for. FAP selects the students participating. Then another type of partnership that we had, more in the initial part of the program, were the parish councils and local institutions very close to the population. Every year we promote meetings with parish councils' staff to raise awareness of the IP. Sometimes GP doctors or local institutions like parish centers, which work directly with elderly, invited participants to the IP. These partners believe PA could be a solution for depression, sadness and loneliness. For me, that promoted the sustainability of this program. [PA manager] PA granted full autonomy to its participants to self-navigate through the duration of the IP and beyond. Each intergenerational match in the program was treated as a unique situation. All the different pairs had different routines and, therefore, various levels of intergenerational contact. The empowerment that each pair gained during IP implementation was well-known. Since PA was grounded on home sharing philosophy, the program did not present a framework of rigid activities that the participants had to follow. Contrariwise, the autonomy on developed activities able to foster closer interactions and meaningful relationships depended on the participants. Some pairs decided to pursue the relationship to the point of introducing their families to each other. In close relationship with the stakeholders, the PA's manager described how IP planning and implementation took into consideration participants' needs and expectations: Each pair is unique. All cases had different routines, needs and expectations, and therefore this is all considered at the beginning of the IP. The participants' families, after a while, begun to interact much more with participants rather than the staff team. In an initial phase the family members asked us In sum, we found evidence that in this case IP sustainability grounded on close relationships with a wider range of stakeholders. For this particular interviewee, those relationships endorsed IP dissemination and a growing number of participants.

Case Study Two-PG
PG stood out from our case study samples for three main reasons. Firstly, for being a familial IP based on a primary school aiming to bring together kin (grandparents and grandchildren) through curriculum activities. Secondly, instead of a mainstream coordinator, this IP had a coordination team composed of two teachers, a psychologist, a social educator, and an academic. And thirdly, its short duration, approximately two years. In concordance with the data analysis the dimensions highlighted by the PG's manager were: intergenerational relations, coordinator's skills, participation in the IP, and communality and institutionalization of the IP (Hierarchy Chart A2, Appendix A). The coordination team had been in the same institution for three years and followed the same students (from the same classroom) in this period. This close relationship with the students permitted a realistic diagnosis of students' main challenges and requests.
The diagnosis made along the interview highlighted some of the students' habits, for instance, with whom these students did their homework and with which members of the family they spent their leisure time. Moreover, the results showed that the figure of the grandparents was stressed only occasionally. When observing the students in the classroom, the lack of attentiveness and focus as well as their difficulties to prioritize the different school tasks were often noticed. The PG coordination team thought that through an IP involving closer interactions between pupils and their grandparents, some learning skills could be achieved. Moreover, the PG team saw the development of an IP as an opportunity to differentiate its classroom within the school: Our intention was to bring together school and families. To foster a real implication of the grandparents in the education of students. Grandparents ought not to feel their role ends because of their age.

[PG manager]
The benefits of this IP described by the coordination team were as follows: many of the curriculum learning skills could be learned through the experience and knowledge of older people; and the idea that grandparents are fundamental figures in a child's life was reintroduced. Furthermore, the PG team was aware that they would face adversities related to school time and curriculum requirements. In this case, however, school curriculum had been the main reason for planning and implementing the IP.
The focus of this activity was using younger ones' expertise on technology, since they were more expeditious, to teach the elders how to use the computer. However, the grandparents provided all the thematic content. [PG manager] The main dimensions for a sustainable IP in the words of the interviewee were intergenerational and coordination team's relationships. PG launched several initiatives to improve IP sustainability, such as asking participants to contribute to the designing of activities, co-developing the IP in order to decrease age stereotypes, and using curriculum activities to transmit knowledge and values.
We tried to place them as equals, in the sense that they all had gifts to share. We thought this would be a great way to work differently in the school environment. . . . learn from each other: learn from the most experienced ones and taught to them as well. [PG manager] PG believed that a successful learning environment ought to be framed on intergenerational principles. This manager valued education in a wider scope, where a multiplicity of socio-educational experience takes place.
The students taught grandparents how to work on the computer; however, the grandparents provided the content. It was very interesting to see these exchanges. [PG manager] Although the PG's manager neither had any specific expertise to implement an IP, nor had attended any IP training course, she explained that had conducted focus groups with the staff to address challenges and difficulties using content from scholarly articles describing other IP: I brought some scholarly articles about IP. With other staff members we read and discussed them, but everything was done spontaneously. I think it would have been an asset to bring scholars from the intergenerational field for our discussions. [PG manager] In addition, our findings revealed that PG used a participatory approach, where each participant's contributions and talents were addressed. Overall, our findings indicated that, in this case, intergenerational relationships facilitated IP sustainability. In particular, the interviewee described various experience of mutual affection and relationships building. Yet, the manager did not mention any particular formal partnerships as an important dimension for program's sustainability.

Case Study Three-PHGM
PHGM was developed in a secondary school. The IP started in 2008 and ended two years later. It aimed to promote the exchange of knowledge and values to endorse a positive perspective on aging. The data analysis showed that the sustainability dimensions highlighted by the PHGM's manager were: partnerships, coordinator's skills, intergenerational relations, co-design, and financing (Hierarchy Chart A3, Appendix A).
The PHGM's manager mainly perceived sustainability as IP continuity beyond its initial financed stage. Continuity was additionally allied with periodicity of the intergenerational encounters: On the first year, there was not a weekly frequency, and I think that somehow [the lack of regularity] creates some obstacles. It is fundamental to engage the groups, and that entails a spatial and temporal interaction, minimum once a week. [PHGM manager] For this interviewee, empowerment was the key dimension of sustainability: empowerment of the stakeholders, the participants, and the coordinator. In the piloting year, the manager participated as a team member and in the second year, became the leading figure since the previous IP manager left for another institution. The students participated actively in the IP planning and design contributing with creative activities and with inviting family members to implement some of those activities. Although lacking theoretical and methodological expertise, this manager found a consultant that could guide her through IP implementation.
Having a consultancy is a key feature to a sustainable IP. Luckily, I found a consultant with an academic background in the area with social and psychological skills. A person who was aware of the small details that might arise during the implementation of the IP. I would advise any IP manager to have an intergenerational consultant. [PHGM manager] Similarly, this manager emphasized at length the vital importance of formal and informal partnerships for a successful implementation of the IP. Despite institutional partners like a day center, students' families played a crucial role in three stages of the IP: (i) supporting students' intergenerational initiatives on weekends, (ii) granting authorization to students to leave the school when required by activities, and (iii) contributing to various activities, for example, leading a history lecture and activity entitled "Matosinhos Past and Present".
With regard to interpersonal empowerment, the interviewee outlined specific attitudes and behaviors that reinforced intergenerational relationships. Grounded on a clear intentionality to mitigate age stereotypes, PHGM prioritized weekly encounters of an hour and a half. At the beginning, some students were reluctant to push wheelchairs, but in the course of the IP the students' views on aging expanded. The manager of PHGM reflected on the feelings and relationships among the participants in the following way: It was clear the progression in terms of affection on the side of some students who were reluctant to participate in the activities with the elderly. This advancement was evident in the visit that students made to the elderly on weekends, with their parents, without any intervention from me.

[PHGM manager]
Certainly, the elderly had their own stereotypes about young people, for example, that the latter are noisy and self-centered, but the IP had brought about a re-orientation toward relationships. It was described that the time in the IP had fostered engagement between the participants. In fact, an old woman asked for permission to call 'my granddaughter' one of the girls. PHGM encouraged its participants to drive into intergenerational values and communication to better understand the 'age-other'.

Case Study Four-UAUS
UAUS is an IP integrated within the community and aimed to contribute to increase social capital. It was started in 2006/07 and it was still in place at the time of interviewing its manager. The UAUS' manager described at length the core intentionality of the IP: to promote bridges between the school and the community and to bring different generations together, for instance, through visiting the school where the older participants had studied, helping older participants to organize family photograph albums, and visiting museums. The manager explained that the main aim of the IP was to foster relationships and capacity of listening and to mitigate age stereotypes. In concordance with the data analysis, the sustainability dimensions highlighted by the UAUS' manager were: intergenerational relations, partnerships, coordinator's skills, participation in the IP, and participants needs (Hierarchy Chart A4, Appendix A). This IP had its origin in intergenerational volunteering. In order to strengthen the intergenerational relationships, weekly meetings took place during the academic year. The manager of this IP commented on the core dimension for a sustainable IP from its point of view: To implement a sustainable IP, it is necessary to touch on the inner depth of human beings. It is when the affections, the relationships, the dreams and hopes are touched that human beings feel welcomed and can welcome others. Therefore, a relationship begins. [UAUS manager] For this interviewee, the intergenerational relationships developed during the IP brought about involvement of the participants and families in the planning of activities, hence gaining a sense of empowerment. In UAUS' case, there were acute reasons for that to happen. The interviewee described participants and families who were highly involved in planning due to their continuing participation in the IP during three academic years. Moreover, the participation of older siblings of the students in the IP in previous years also encouraged participation. During the interview, there was a continuous referral back to the intensity of the relationships in the program associated with feelings of trust.
The weekly meetings promoted closeness, and because of that trust grew. With time, it is not only two people that met up every week-they became friends. That was what I observed in the IP. [UAUS manager] In the context of relationship building, within the IP, another dimension that contributed to sustainability was the particular relationship among peers involved in the program. The UAUS' manager observed, during the course of the IP, deeper bounds between the students participating than between classmates. The participating students were not in the same school year and the IP was an opportunity for them to come close and develop a friendship that otherwise would have been more laborious to entertain.
The research evidence indicated that the idea of a rationale for IP sustainability on autonomy, empowerment, and intergenerational relationships is relatively new for educational IP managers in the area of Porto. Nevertheless, the idea of IP sustainability based on continuity of the IP is not. Indeed, one could argue that the rational suggested by the authors and confirmed by the results, it was possible to develop a broad inclusive definition of IP sustainability that might guide further development in the intergenerational field.

Conclusions
This article has examined how autonomy, empowerment, and intergenerational relationships are embedded in educational IP as dimensions for sustainability. Accordingly, and in light of the managers' experience and insights, the distinction between sustainable and unsustainable IP is problematic. On one hand, at first glance, the four interviewees were somehow reluctant to envisage sustainability beyond the continuity of the IP. The four case studies continued after an initial pilot year and that was felt by their managers to be a success in terms of sustainability. On the other hand, cases such as PG and PHGM illustrate in detail how IP sustainability, despite a shorter program duration, may be approached through a new perspective. Both the managers described co-design and a participatory approach as fundamental elements to deem their IP sustainable. PHGM emphasized consultancy as a pathway to counter the lack of expertise. Yet, the managers of PA and UAUS, who had previous professional experience working with generations involved in their IP, and the manager of PHGM provided opportunities for developing autonomy and empowerment as well as a clear intention to foster relationships between the participants. PA and UAUS managers, involved in the two oldest IP studied, exemplified how previous professional experience working with both generations may nurture an intentionality to foster intergenerational relationships, in particular, to strengthen community bonds.
Autonomy and empowerment framed IP sustainability in the latter cases. PA and UAUS indicated that IP autonomy does not necessarily need to be dependent on the managers' persona. This concept means to describe the type of character of managers' representation roles. An IP cannot just be centered on the leadership capacities of its manager. The results showed the complexity of an IP, and therefore sustainability cannot be framed in one person's character or communication style only. The results indicated that the web of relationships between all the participants, stakeholders, and the management team is the fuel for a sustainable IP. Contrarily, in the case of PG and PHGM, both of these IP were started under the initiative of their managers, who became more relevant in terms of program sustainability. In general, the interviewees highlighted the need for educational IP to be embedded into the school infrastructure, something that some of them called 'institutionalize the IP'. This belief supports findings by [30] who suggested that IP which are part of an institutional plan of activities have more chances to be sustainable. We recommend future intergenerational programs to be built in the fundamentals of an institutional plan of activities. In our study, two cases-PA and UAUS-had already been integrated as part of their organizations' missions and goals. Hence, fostering the commitment of participants to attend in the future was far more emphasized as a condition for sustainability. The four interviewed managers agreed that evaluation procedures were also a crucial factor for the sustainability of the IP. Motivation to pursuit complex and valid evaluation methods also reflects willingness to withdraw from anecdotal evaluation procedures [47][48][49]. Nonetheless, there little evidence that evaluation procedures were clearly taken into account, as identified in the literature [11,49]. Similarly, annual reports were rarely mentioned The most relevant conclusion stemming from the presented study is that understanding the sustainability of IP solely on the basis of securing continuation of the program is insufficient to capture sustainability fully. In the introduction, we argued that beyond sheer continuity, at least autonomy/empowerment of stakeholders and the existence of intergenerational relationships should be taken into account. Our analysis supports this initial consideration. All four cases have listed dimensions of sustainability other than duration, such as capacity, to establish strong partnerships, co-design, participants' involvement, stakeholders' and coordinator's empowerment, and autonomy in the decision-making process to develop the program, and counting on a web of relationships between generations and individuals at stake. Therefore, one lesson to be learned is that IP sustainability should be dealt as a complex construct deserving a more elaborated and systematic approach.
We are aware of some limitations of our study. For instance, the sample utilized cannot be considered representative nor generalizable, as generalization was never intended. Given the paucity of research about IP sustainability, views expressed by our four program managers may well be of interest to other intergenerational practitioners in the country and be useful to understand key components of sustainability in similar educational IP. Another limitation has to do with the need to use ad hoc conceptualization to make our study possible. Since the area of IP sustainability is so underdeveloped, an initial set of foundational concepts and sustainability dimensions had to be presented ex novo so that the research could be carried out. Certainly, the suggested conceptualization must be subject to critical review in future studies. Moreover, the study draws on a small sample, and the potential problem of selection bias is inherent in any qualitative study of this nature. This is a limitation of the research, which could be addressed in future studies specifically targeting other IP all over the country and not only in the Porto area. The research refers to data that cannot be considered statistically, but instead represents in-depth views and experience of specific IP managers in the Porto area of Portugal, which was purposively sampled.
It is contended that educational IP sustainability is a significant area in the intergenerational field that needs further attention toward a deeper understanding of how successful intergenerational programs work. Future theorizing in this area should go beyond just looking at normative procedures behind IP duration and consider IP sustainability as a complex conceptual framework that in the past has failed to identify the role played by autonomy, empowerment, and intergenerational relationships. Therefore, more research efforts are required around IP sustainability since its most extended conceptualization, i.e., sustainability as mere duration in time, seems inadequate to address other factors behind the sustained impact of intergenerational programs.
Author Contributions: C.A. conceived the study as part of her Ph.D. thesis (Azevedo, 2017). C.A. designed the methodology, carried out the fieldwork, software, and data analysis. C.A. took the lead on writing-original draft preparation; writing, C.A. and M.S.; writing-review and editing, C.A. and M.S.
Funding: This research received no external funding.

Acknowledgments:
We would like to express our sincere appreciation to all the IP managers involved in fieldwork who generously shared their experience and insights. The drafting of this article was partially accomplished while Cláudia Azevedo was a LARNA Research Fellow (Oxford Institute of Population Ageing, University of Oxford) and Mariano Sánchez was on a stay as Visiting Scholar in Population Studies (Population Studies and Training Center, Brown University).

Conflicts of Interest:
The authors declare no conflicts of interest.
Appendix A Table A1. Foundational concepts for mapping and interview protocol development.

Concept Objectives Explanation
Intergenerational programs Identify and characterize IP developed in Porto, Portugal Initiatives that go beyond intermittent contact between people of different generations. IP, by definition, ought to have a clear intentionality and a structured design that aim to bring people from different generations together with a beneficial goal in mind and evaluation procedures.

Sustainability
Explore qualitatively the sustainability or the absence of sustainability in IP in Porto, Portugal We accept that the sustainability of IP might be partially linked to the program's continuity. However, we understand sustainability in a plural and qualitative framework, wherein the IP demonstrates autonomy. The sustainability of IP does not depend on a single person, but on the web of interactions and relationships.

Good practices of sustainability
Establish key dimensions for the development of sustainable IP in order to be replicated Sustainability procedures in place by those who are involved in the successful practices of IP.
Sustainability 2019, 11, x FOR PEER REVIEW 12 of 17 Appendix A Table A1. Foundational concepts for mapping and interview protocol development.

Concept Objectives Explanation
Intergenerational programs Identify and characterize IP developed in Porto, Portugal Initiatives that go beyond intermittent contact between people of different generations. IP, by definition, ought to have a clear intentionality and a structured design that aim to bring people from different generations together with a beneficial goal in mind and evaluation procedures.

Sustainability
Explore qualitatively the sustainability or the absence of sustainability in IP in Porto, Portugal We accept that the sustainability of IP might be partially linked to the program's continuity. However, we understand sustainability in a plural and qualitative framework, wherein the IP demonstrates autonomy. The sustainability of IP does not depend on a single person, but on the web of interactions and relationships.

Good practices of sustainability
Establish key dimensions for the development of sustainable IP in order to be replicated Sustainability procedures in place by those who are involved in the successful practices of IP.