Procedures and Data Basis

Abstract

The Ageing as Future project combined and used a variety of multidisciplinary, multicultural, multimethodological, and longitudinal approaches. The chapter provides an overview of the approach and the process of the surveys of the various subprojects in Germany, the USA, Hong Kong and also in Taiwan and the Czech Republic.

The Ageing as Future project investigates influences of structural dynamics in modern societies on personalized and generalized views on ageing, time management and preparatory and future oriented actions in the life course using a variety of methodological approaches. Within this framework, multidisciplinary, multicultural, multimethodological, and longitudinal approaches were combined. From a psychological, sociological, and gerontological perspective, central constructs of the three closely interrelated topic areas were examined over a period of up to 10 years in initially three and in the last survey phase five countries (Germany, the USA, Hong Kong, Taiwan, and the Czech Republic). Different empirical methods could be used and combined in different parts of the project: problem-centered and partly biographical-narrative interviews, structured questionnaire surveys, and online surveys. The following chapter provides an overview of the approach and the process of the surveys of the various subprojects in Germany, the USA, and Hong Kong and, from 2016, also in Taiwan and the Czech Republic. Figure 2.1 provides an overview of the thematic focus and methodological approaches in the three interlinked subprojects.

Fig. 2.1

Main research topics and methods of the three subprojects

The three central topics of the project “Ageing as Future” were investigated considering the different emphases of the participating subprojects and countries over the course of three joint survey waves at intervals of 5 years as well as additional intermediary surveys with online questionnaires at 2-year intervals. The focus of the questionnaire study subproject was to examine the determinants, domain specificity, and effects of views on ageing; the subproject of the online surveys focused on determinants, expectations, and preparatory and future actions; the subproject of the qualitative interviews focused especially on the topic of time management and time sovereignty.

At the beginning (in 2008/2009), the focus was more on the investigation of context- and domain-specific influences on views on ageing and on the experience of the ambivalence of temporality structures in the life course. The second joint survey wave (2013/14) then focused on aspects of the interplay between views on ageing and ageing preparation from different disciplinary and methodological approaches. In this second wave, data were analyzed regarding cultural differences. In the third general wave of the survey (2018/2019), further focal points were added, which focused on the fourth phase of life, vulnerability, and dealing with the finitude and the end of life. Furthermore, three additional intermediary surveys were conducted as part of the online surveys in 2012, 2016, and 2020.

In the following, the three methodological approaches (questionnaire, online surveys, interviews) are described in detail. In a final paragraph, we address issues regarding the translation of the survey instruments and guidelines into the languages of the participating countries, the network process among the subprojects, and the procedure for archiving the data for future research on these topics.

2.1 The Questionnaire Study

A structured questionnaire was developed for the project, containing relevant constructs for all the complex, content-related questions of the project (views on ageing, preparation for old age, time experience, and management), with the focus on a differentiated assessment of age-related perceptions and attitudes. Table A1 in Appendix A provides an overview of the main content areas of the instrument. Almost all components of the questionnaire were newly developed for the purposes of the project to provide a thorough and most detailed coverage of the relevant constructs. Scales were developed for assessing views on ageing, preparation for old age, and the subjective experiences of age and time in a domain-specific way. Furthermore, personalized (i.e., perceptions related to oneself and one’s own ageing) and generalized (i.e., attitudes related to the group of older people in general) constructs were assessed separately. With such differentiated instruments, a multidimensional and multidirectional assessment of the experience of old age and age-related behavior is possible, which can also depict the complexity of age-related attitudes within single individuals.

The multitude of constructs from the field of ageing experiences and ageing behaviors as well as the multidimensional assessment of the constructs is a unique feature of the questionnaire study. This approach goes beyond existing panel studies, in which age-related constructs are typically regarded as homogeneous and only assessed via one-dimensional scales (e.g., positive vs. negative views on ageing) or via individual items (amount of financial provision, general experience of old age, e.g., subjective age, extent of experienced age-based discrimination).

The core components of the instrument were used in almost identical versions across all measurement points to enable longitudinal comparisons and thus to be able to separate age and cohort effects from one another. Additional constructs were included in the questionnaire instrument during the thematic extensions of the project during later measurement occasions (see Appendix, Table A1).

2.1.1 Test-Theoretical Quality Criteria and Measurement Invariance of the Questionnaire Scales

Factor and reliability analyses were used to validate the measurement-theoretical properties of the newly developed scales. In particular, for the instruments that assessed views on ageing and preparation for old age, the proposed domain-specific structure could be validated by confirmatory analyses. It appears that attitudes and behavioral tendencies toward age-related topics in different life domains (e.g., family, work, leisure, health, appearance, friends) are largely independent of one another and each represent independent dispositions of belief and behavior (Kornadt & Rothermund, 2011a, 2014; Kornadt et al., 2020). The measurement accuracy (reliability) of the newly developed instruments is satisfactory to very good.

A major goal of the project is to systematically compare age-related attitudes across age groups and countries. Such comparisons assume that the scales measure the same construct in the different groups and cultural contexts. Technically, this question is about the so-called measurement invariance of the scales, which can be tested by comparing the correlations and pattern of means of the scales and its constituent items in the different groups (Milfont & Fischer, 2010). Corresponding analyses could confirm measurement invariance of the instruments across age groups and countries (de Paula Couto et al., 2022a; Kornadt et al., 2019; Voss et al., 2018b).

2.1.2 Design, Sample, and Recruitment of the Questionnaire Study

At its core, the questionnaire study uses a cross-sequential design (Schaie & Hofer, 2001) in which the same constructs/variables are collected from individuals in an age-stratified sample at multiple measurement time points separated by intervals of 5 years. Such a survey approach allows for the identification and separate estimation of age and cohort effects: Age-related changes are estimated via longitudinal changes, whereas cohort effects are estimated by comparing age groups within the same measurement time point. Time-of-measurement and repeated-measurement effects can be analyzed by comparing individuals of the same age who were tested at different measurement times; for this purpose, data are also compared between participants who are tested for the first time and those who have already been interviewed repeatedly.

For the German subsample, three measurement points were realized at 5-year intervals (2009, 2014, 2019); for the samples in the USA and Hong Kong, two measurement points are available (2014, 2019); for Taiwan and the Czech Republic, one survey wave was conducted (2019). The participants in the German sample covered the age range of 30–80 years at the first survey time point. We stratified the sample to ensure that the five cohorts (30–40, 41–50, 51–60, 61–70, 71–80) were each equally represented and had a balanced gender ratio. In the 2014 and 2019 follow-up surveys, samples were recruited in each of the newly added countries whose age range corresponded to the German sample—now 5 and 10 years older, respectively (2014 survey, age range 35–85 years; 2019 survey, age range 40–90 years). For the follow-up surveys (Germany: T2, T3; USA, Hong Kong: T3), participants from the previous survey(s) were first contacted and asked to participate again. In addition, new participants were recruited to obtain a balanced sample by age and gender within the respective measurement time points within each country.

Participants were recruited in different ways in the various countries. For the German sample, we were provided with address lists by the residents’ registration offices of the cities of Jena and Erlangen, from which age- and gender-stratified random selection of individuals were contacted in writing and asked to participate in the research project. Participation was compensated with an expense allowance. In the USA and the Czech Republic, recruitment was organized by field research companies. Here, the individuals were from the Wake County region (USA) and the cities of Pilsen and Brno (Czech Republic). In Hong Kong and Taiwan, individuals were recruited through local contact points (municipalities, retirement centers) and field research firms. The survey in Taiwan was limited to residents of the city of Tainan.

Table B1 (Appendix B) provides an overview of the respective sample sizes for a total of three measurement time points in the participating countries. This also includes information on demographic characteristics as well as the proportion of individuals for whom longitudinal data are available for the respective intervals (T1–T2, T1–T3, T2–T3, T1–T2–T3). Despite different recruitment strategies in the various countries, samples were drawn that can be considered approximately representative of the respective age ranges, although certain social groups are underrepresented (especially older people living in institutions).

2.2 The Online Survey Study

The online survey investigated ageing preparation behavior in the context of subjective time and future perceptions over time. The online survey study focused on assessing ageing preparation regarding central areas such as finances, care, housing, loneliness, and death and dying. An important role was played by the way in which personal deadlines for the planning of preparatory action are shifted or adapted to the respective subjective constructions of one’s own future over time.

A structured online survey was programmed for the project, which focused on an activity-related, differentiated, and everyday assessment of preparatory and future-oriented actions, as well as on a multidimensional query of various aspects of the personal experience of time and the future. An overview of the content areas of the online survey is given in the Table A2 in Appendix A.

Some central components of the online survey were developed completely new for the project. At the same time, these new constructs were supplemented by a survey of numerous already well-established survey scales and instruments from ageing and personality research to enable the most reliable and robust classification of the findings and to ensure the validity of the surveyed constructs.

For the areas of ageing preparation and thinking about the future, descriptive graphical elements were used in the online survey, which made it possible to capture even complex issues of ageing preparation, such as subjective deadlines for preparing or personal evaluations and assessments, as intuitively and as closely as possible to everyday life. This procedure allowed in particular a differentiated assessment of topic-specific and multi-layered aspects of future action in connection with subjective views of one’s own future. In addition, it was also possible to use some of the questions from the questionnaire study described above in the online survey, which also allowed a comparison and alignment between the findings from both studies.

All core components of the instrument were retained in the course of the online survey study in predominantly identical form across all measurement points in order to enable longitudinal comparisons and at the same time to be able to separate age and cohort effects from one another.

2.2.1 Reliability and Validity of the Online Survey

In the case of surveys with online questionnaires, it is often objected that these entail special demands for the respondents and require, for example, knowledge in the use of computers and the Internet. During the project, the countries involved made great progress in digitization in this respect, which is also reflected in the increasing convergence of samples between online and questionnaire surveys over time (see Appendix B, tables B1 and B2). However, the chosen approach of the online survey also appeared to be particularly well suited for investigating some of the central questions of the project Ageing as Future for several reasons:

First, it made it possible to include filtering guidance in the programming of the online survey, where faster and easier processing was possible because questions were only asked if they matched previous answers (e.g., if only parents were asked about their children).

Secondly, it allowed the use of graphic elements in some places, where this seemed necessary, to dispense with predefined answers or rating levels. For example, the subjective position in one’s life course between the beginning and the end of life was surveyed with a visual analog scale, in which the respondents were able to set a freely movable symbolic slider bar at the point in their life course at which they believed to be currently located.

Third, in the online surveys, it was also possible to divide the participants into different groups in which a task (e.g., planning the next day) could be completed under different conditions (e.g., comparison of planning for a “relaxed” day versus an “active” day; John & Lang, 2015).

Fourth, the online surveys made it possible to reach different target groups from a wide variety of contexts, for example, by targeting them in online forums, social networks, and through already existing lists of interested individuals, which also allowed for a high heterogeneity of the sample in terms of composition by age and social background. Regardless, as is known from other online studies, certain social groups such as women and more highly educated individuals (e.g., with university degrees) tended to be overrepresented in the online surveys. However, due to the heterogeneous distribution of such characteristics in the sample, possible biasing influences on the results could mostly be statistically controlled. However, more extensive and undetected biases in the findings due to unobserved characteristics in the sample selectivity cannot be ruled out here either. One strategy for dealing with this problem was to include survey instruments from the questionnaire study (see Sect. 4.1) and from representative surveys (e.g., German Age Survey), so that it was also possible to compare the findings based on such marker variables to detect effects of sampling bias. In addition, study participants were recruited somewhat differently in each of the participating countries, depending on their general conditions. In China, participants for the online study were recruited via a company specifically commissioned for this purpose, whereas in Germany and the USA, interested individuals were recruited for participation via existing pools and newspaper appeals.

Fifth, the online survey method enabled a simplified transfer of the survey and query program into other languages such as English, Chinese characters, and Czech, and the surveys could be conducted in the different partner countries from a common computer center at the University of Erlangen-Nuremberg and processed in a common database.

2.2.2 Design, Sample, and Recruitment of the Online Survey Study

The online survey study relies on a mixed cross-sectional and longitudinal design that began with initial pilot surveys in Germany in 2009. Table B2 (Appendix B) provides an overview of the respective sample sizes for five measurement points in Germany and three measurements in partner countries in 2009, 2012, 2014, 2016, and 2018. In the first phase of the project in 2009–2012, the focus was initially on developing the survey procedure and the scales. A repeated data collection then followed every 2 years starting in 2012, with occasional additions to the survey instrument in the different waves.

In all participating partner countries, the participants were recruited in an equal age range of generally between 20 and 90 years. The original German sample of 591 participants was expanded in 2014 to include 140 participants from the USA and 348 from Hong Kong. Then in 2016, 446 participants from Taiwan were added and, in 2018, another 529 participants from the Czech Republic. Thus, a total of 2054 participants from 5 countries took part in the online surveys at least once.

In 2016, across all participating countries, approximately 55% of those who had also participated in 2012 took part in the study again. Across all survey data points between 2009 and 2018 and all participating countries, a total of 3644 participated in the online surveys. Of the 1717 participants from Germany, 30% participated at least twice; of the 315 from the USA, about 59% participated at least twice; of the 448 from Hong Kong, 61% participated twice; of the 635 from Taiwan, 15% participated twice; and the 529 from the Czech Republic participated in only one survey in 2018. In a recent wave of data collection in Germany, which took place conclusively in 2020, a total of about 2,500 individuals (returning as well as first-time) participated, with a take-up rate between 35% and 70% (based on previous waves of the survey). The data from this survey wave have not yet been included in this chapter. An overview of the respective sample sizes in the participating countries for at least two measurement points in each case is given in Table A2 in Appendix A. Data on age, gender, and education are presented, as well as the proportion of participants who repeatedly took part in the surveys. For reasons of parsimonious presentation, only information for the proportions of those who had participated in the previous survey (T2–T3, T3–T4) and in the first survey (T1–T2, T1–T3, T1–T4) in addition to the current survey is provided there. Despite partly different recruitment strategies in the different countries, the samples obtained reflect a sufficiently large heterogeneity to be able to statistically test and control for possible biases due to recruitment selectivity.

2.3 The Qualitative Interview Study

Unlike quantitatively oriented social research, which operates with large datasets, qualitative empirical studies do not aim at statistical representativeness, i.e., at being able to make valid scientific statements about large population groups, e.g., about older people in Germany, by means of appropriate sampling and other methodological precautions. On the contrary, qualitative social research deals with small numbers of cases, and typically the aim is to trace social patterns of interpretation, action orientations, and behavioral structures by examining individual cases (cf. Flick et al., 2019). Somewhat boldly, it could be said that qualitative studies are less concerned with the breadth and more with the depth of their subject matter. Nevertheless, they also have the aspiration—more or less pronounced, depending on the approach—to infer the general aspects of a larger context from the specifics of the individual case, i.e., in our case, to deduce from intensive discussions with quite a few older adults quite reliable findings about structural aspects of time management in old age. The purpose of qualitative research in this sense is to ensure the “theoretical representativeness” of its empirically derived concepts (cf. Muckel, 2011). Ideally, the space of possible positionings of social subjects on questions of one’s own life, on the one hand, and of social life, on the other, is then delineated in such a way that light is thrown on their qualitative structure and thus on the frame of what is socially sayable (and doable) about a specific issue (while the quantitative distribution of more or fewer people on the reconstructed positions is not known). It is in this sense, for example, that the different varieties of everyday-time and life-time styles in old age that are identified in the course of our research project or the individual handling of the knowledge about the finitude of one’s own existence are to be understood: We cannot say—at least not with qualitative methods alone—how widespread the individual variants of structuring time or dealing with finitude are among older people; but we can say that empirically there is a limited number and a specific structure of corresponding patterns of action and orientation.¹

Against this background, our qualitative research within the project Ageing as Future did not follow a completely open conception regarding the collection of empirical data, since the specific research interest was already set in advance by the project context: We wanted to ask older people about their time-related perceptions and interpretations as well as about their forms of shaping time in everyday and practical life. In other words: We were not interested in “everything” concerning old age and ageing and not exclusively in the respondents’ subjective structures of relevance, but we pursued a specific question, which made it seem necessary and legitimate to orient the construction of the instrument for data collection to this very question. Consequently, we opted for the data collection method of the guided, problem-centered interview, which we enriched with biographical-narrative components (see Appendix A, Table A3 overview of topics and contents of the guidelines used).

The “problem-centered interview” (PCI) is a semi-structured interviewing method developed to a large extent by Andreas Witzel (2000), which—as the name suggests—orients the interview specifically to the researcher’s problem of interest, in our case the time agency of older persons. The interview is based on a pre-constructed interview guideline that allows the interviewees to speak as freely as possible with the help of narrative impulses, but still gives the interviewer the opportunity to lead the interviewees back to the “actual” problem again and again. As much as the interview is thematically directed and pre-structured, it is important in this context to maintain the greatest possible openness and flexibility for unexpected turns of conversation and for the idiosyncrasies of the interviewees, thus avoiding a schematic and rigid processing of the questionnaire (“guideline bureaucracy”, cf. Hopf, 1978). As with all forms of qualitative interviews, the appropriate formulation of the initial question is of decisive importance for the content-related fruitfulness of the PCI. If it is successful, it will stimulate a detailed, self-determined initial narrative on the part of the interviewee, which can then be followed by comprehension-generating follow-up questions or further narrative impulses from the interviewer. Ideally, the pre-planned questions can be introduced and inserted into the interview as seamlessly and naturally as possible, so that the interviewee’s own sense of meaning and relevance structures as well as the researcher’s interest can be considered.

In the first wave of our qualitative research, we began the interviews by asking respondents what they associated with the term “retirement.” Generally, this was a very fruitful way of starting the interviews and led us, sometimes directly, sometimes via shorter or longer detours—e.g., by asking about the circumstances of retirement or the restructuring of everyday life after leaving employment—to the core “problem” of time perception and time management in old age that we were interested in. The request to the interviewees to describe the course of the respective previous day as precisely as possible, which was usually placed quite early in the interview, also proved to be extremely fruitful and a source of diverse narrative connections. As the initial question about the personal significance of retirement appeared theoretically saturated at the end of the first project funding phase, so that no structurally novel narratives in this regard were to be expected in further interviews, we opened the interviews of the second phase with the more biographical narrative question about the interviewee’s most important stages of life. In its concrete formulation, this question was a result of the exchange with the American research team, because for US interviewees a biographical thinking in terms of individual, successive, and relatively self-contained “life chapters”—including a “last chapter” of old age—seemed to be pretty familiar. In the German case, this approach yielded an extremely interesting result (to be discussed further in Chap. 5) that the subjective life narrative in stages often ended with the end of the working life, i.e., that “old age” did not seem to be a chapter of its own in the personal “book of life” for quite a few interviewees.

In the first wave of interviews, we also used visual methods, namely, photographs with symbolic references to age and finitude (a tree changing across the four seasons, the annual rings of a tree, the sandblast in an hourglass) as well as highly stylized drawings (different forms of ascending and descending or horizontal serpentine lines as well as different variants of spiral lines) all of which were intended to represent lines of life. The request to the interviewees to choose the most appropriate representation for their own life course or their image of ageing also often led to detailed and rich impromptu narratives. Interestingly, it turned out that certain images (such as the seasonal tree) “worked” cross-culturally, while others did not (which is why, for example, the research team in Hong Kong refrained from showing the annual rings image after the first interviews).

Our methodological approach to collecting and analyzing the data was closely aligned with the established methodology of Grounded Theory. This qualitative research approach, which goes back to the American sociologists Barney Glaser and Anselm Strauss and is often briefly apostrophized as “GTM” (cf. Mey & Mruck, 2011), aims in its core at a consistently empirical—empirically founded or “grounded”—theory building. Accordingly, analytical concepts and categories must be consistently drawn and developed from the empirical material—in this case, the transcribed wording of the interviews—and not, for example, through abstract derivations from existing theories (in our case, for example, from the given arsenal of sociological theories of age, subjectivity, or action). The GTM also seemed to be suitable for our project because it understands social events as structurally situation-dependent: as a question of everyday practice, the real dynamics and subjective interpretation of which are not predetermined, but only emerge in practice itself and are therefore only revealed to the researchers through practice.

In terms of research practice, this has two implications. On one hand, in the process of interpreting the data, there is a constant switching back and forth between the close reading of the empirical material and the theorizing work that gradually abstracts from it.² On the other hand, the composition of the sample, i.e., the group of cases to be studied, follows the principle of theoretical empiricism, which is to a certain extent complementary to empirical theorizing: As in the research project presented here, the theoretical findings that emerge from the analysis of the initial interviews determine the further recruitment strategy of interview partners—and thus ultimately the structure of the sample. However, this principle of theoretical sampling was broken by the decision made at the beginning of the project to interview people from two different age groups (60- to 70- and 75- to 85-year-olds) and, in the second wave of the survey, increasingly people of advanced age (over 80 years). Beyond this, however, the characteristics of the interviewees to be sought in the next research step resulted from the empirically based theoretical findings generated beforehand: If in one case the status of living alone or being widowed turned out to be significant for the concrete form of everyday or lifetime activities, then in the next step, we sought married or older people with partners as contrasting cases. Similarly, the empirical significance of care work obligations for women’s individual time management prompted us to comparatively include older men who care for their partners in the sample.

As a result, a total of 80 interviews were conducted in the German case (plus 60 in the the USA, Hong Kong, and Taiwan, respectively, and 30 in the Czech Republic). Although the samples did not prove to be representative of the respective national populations, they were quite heterogeneous in terms of sociodemographic characteristics and social structure (cf. overview of interviewees in Appendix B, Table B3). In the German sample, it was possible to carry out second interviews with one and the same person in a total of 18 cases due to the two survey times within the framework of the two project funding phases (but also by way of resorting to persons interviewed in earlier research projects).³ The first respondents were recruited with the help of placards in senior citizen facilities, newspaper advertisements, a (theoretically justified) snowball principle, and existing databases with test persons from the quantitative subprojects. The interviews took place in a Western and in an Eastern German city and their immediately adjacent municipalities; both cities had a similar number of inhabitants and sociodemographic characteristics as well as a comparable social infrastructure.

Essential parts of the outlined methods of data collection and analysis were adopted by the international cooperation partners and carried out in an analogous manner but adapted to local conditions and to the professional qualifications of the respective project teams. The American survey took place in a major Midwestern city and its catchment area, the Czech survey in a major city. The findings from the highly internationalized metropolitan region of Hong Kong could be compared in the second funding phase with data from a more rural, culturally traditional region of Taiwan. In the case of Hong Kong, the special feature was that the interviewees were recruited from among the participants in the quantitative studies of the Hong Kong subproject, which meant that their sociodemographic and socio-structural composition was particularly balanced.

In the German sample, on the other hand, but also in the American sample, there was ultimately a clear excess of respondents from middle-class households (a circumstance that will be problematized in Chap. 5). In this volume, the focus of presented research findings lies on the data from the German study. In this German context, it should be notated that the age difference between the young interviewer and the older, in some cases very old participants, did become a topic in some of the interviews. At times, this may have influenced the participants’ positions on the issues negotiated in the interviews.

The methodological challenges of interculturally comparative, multilingual qualitative research on ageing have been extensively and recurrently addressed in the long process of our international research collaboration, culminating in a joint scholarly article on the issue of the respective researchers’ “operational blindness” to the cultural, social, and institutional specifics of their local contexts (Lessenich et al., 2018).

2.4 Interconnection of the Subprojects

The methodological advantages of the Ageing as Future project stem from the diversity of complementary methodologies and the comprehensive datasets generated by the project through the combined expertise of researchers from different disciplines and countries. Quantitative studies were combined with qualitative interviews within and across countries and conducted over the 10-year period between 2010 and 2020. All questionnaires, scales, and interview guidelines were developed in close collaboration between the different parts of the project and with the international collaborating partners. The development of the instruments took place in a multistage process, which included interviews and group discussions with older adults. Although each of the subprojects had its own research focus, there were also overlaps between the substantive topics of the subprojects as well as overlaps in the samples studied which allowed an exchange of results and a combined analysis of the data. In the following, we first present the procedure for the development and translation of the scales and questions of the survey instruments that were used and, for the most part, newly developed. Following on from this, we present examples of some of the interconnections and cross-references between the various subprojects to illustrate the added value of the resulting findings. Finally, the archiving of the resulting data corpus and its provision for future research and for young scientists will be discussed.

2.4.1 Development and Translation of the Newly Developed Scales

Each measurement instrument and the interview guide went through a carefully executed process of translation and back-translation and were piloted and optimized for international use before being employed in the USA, China, Taiwan, and the Czech Republic. This process of selection and translation contributed to the good statistical properties of the measures, constructs, and scales used in the Ageing as Future study. For most of the newly developed scales, open-ended interviews on the respective topics were first conducted with people of different ages to sample the domain diversity and the range of essential content on these topics (Kornadt & Rothermund, 2011a, 2014). In a next step, this content was translated into a standardized questionnaire format and tested on pilot samples. Based on these results, the final version of the German-language questionnaire instrument was created.

For the surveys in the USA, China (Hong Kong, HK), Taiwan (TW) and the Czech Republic (CZ), the German questionnaire was translated into the respective national languages. An elaborate procedure was chosen in which the first translation was back-translated into the source language by another independent person and compared with the original version by the developers of the study. In the case of deviations, the translation was modified again to reflect the items of the original version in the translated version as optimally and meaningfully as possible. For the English and Czech versions, the translation was based on the German questionnaire version in each case, while the Chinese questionnaires were translated based on the English questionnaire. All translations were done by people who have a background in ageing research and who speak the target language of the instrument as their native language and are also fluent in the source language.

2.4.2 Main Topics and Interconnection of the Subprojects

All three subprojects—the questionnaire, interview, and online survey—within the Ageing as Future project have investigated different focal topics in close relation over more than 10 years in the period between 2009 and 2019 in the participating countries Germany, USA, Hong Kong, Taiwan, and the Czech Republic. Figure 2.2 provides an overview of the chronological course of the overall project and the respective focal points within the various subprojects. In the sample sizes that are shown, no distinction was made between participants who participated repeatedly and those who participated for the first time. As a rule, all surveys always contacted respondents from previous survey waves as well as included new participants for each study. A detailed and complete overview of the characteristics of the samples studied longitudinally can be found in Appendix B.

Fig. 2.2

Overview of the three subprojects and the different measurement time points

Note: Targeted age ranges are shown. Deviations of the realized samples (Appendix B) from these targeted age ranges result from ad hoc recruitments of new participants for later surveys

In Fig. 2.2 we have refrained from showing the content-related interconnections of the projects at the respective levels in detail. For example, there was a continuous exchange of research content within the working groups in Germany between 2009 and 2012, regarding the respective main areas of research and questions, as well as regarding the newly developed survey instruments. From 2012 onwards, additional research partners from Hong Kong and the USA could be integrated into the project Ageing as Future. The exchange and networking of the subprojects was also continued and intensified in the participating countries. In Hong Kong, for example, the surveys for all three subprojects were pooled at the Chinese University of Hong Kong. In the USA, the subproject on qualitative interviews was conducted at the University of Kansas and the two subprojects of the questionnaire study and the online surveys at North Carolina State University in Raleigh. As of 2016, it was also possible to involve research groups from Taiwan (Tainan University) and from the Czech Republic (University of Prague) in the project. The networking and collaboration between all participating subprojects and research groups included more than 30 researchers from 5 participating countries and pursued three main goals. First, all subprojects, in addition to each project’s own focus and project-specific scales and questions, shared survey instruments and topics on views on ageing, ageing preparation, and time management. Despite the specific focus of each subproject, it was thus also possible to establish cross-references, validations, and replications to the analyses and findings of the other subprojects.

Second, in all participating countries, there were also numerical overlaps in the respective samples studied, of which data are thus also available from at least two subprojects. For reasons of space, we do not present these overlaps here. The data generated in this way primarily served the methodological validation of the newly developed scales and content-related questions, but also allowed, for example, the investigation of in-depth case studies in which a large number of data are available for individual persons over a longer period of time.

Third, and finally, networking was also evident in the participation of the various countries, which made it possible to examine and deepen culture-specific influences on observed contexts and findings of the subprojects.

2.4.3 Archiving and Preparation of the Datasets

All data collected as part of the Ageing as Future project will be stored in data archives accessible to the scientific community worldwide at the conclusion of the project and thus made publicly available for research and secondary analyses. Archiving of the data material of all qualitative surveys was also ensured at the conclusion. Thus, the corresponding datasets are available for scientific reuse at the Leibniz Institute of Psychology⁴ (ZPID; questionnaire study and online study) as well as the qualitative interviews at the research data center Qualiservice at the University of Bremen.⁵