The LSN Network Study (ancillary study)
Contact: Theo van Tilburg
- Sample and Data collection
- Response on the network level
- Overview of questionnaire
As a part of the “Living arrangements and social networks of older adults” research program, 673 of the respondents of the Main Study participated in a Network Study. This study, a so-called multi-actor study, was constituted as the data collection of a research program into “Reciprocity of social support in the network of personal relationships of older adults”.
The aim of the Network Study is to collect more data about the features of the networks of older adults, and to conduct research into changes in the characteristics and the functions of the network. Three differences between the Network Study and the Main Study are striking. First, the questionnaire of the Network Study is more detailed about the supportive exchanges between older adults and their network members and about other characteristics of their relationships. Second, the Network Study focusses on changes in a fixed selected part of the network, while the LSN Main Study and the successive LASA survey focus on a changing personal network. Third, (a selection of the) network members participated in the Network Study as respondents. Although the network is still ego-centric, adding information obtained from network members makes it possible to analyze the structural features of a “full” personal network, in addition to structural characteristics like the network size that can be assessed from “star” networks.
Figure 1 gives an example of a “star” network. The network consists of the “anchor” of the network, eight persons and their relationships with anchor. The anchor is the respondent of the NESTOR-LSN main survey and graphically represented as the middle of a star. In the interview of the Main Study the anchor of this example mentioned at least eight persons with whom he is in touch regularly and who are important to him: his wife, his son, who is a member of the household, his daughter, one of his brothers, a neighbor, a colleague, someone who is known from an organization and a friend (see LSNa047). If he mentioned more than eight persons, the eight network members were selected with whom contact is most frequent (see LSNa047). When we gather information about the supportive content of these eight relationships, we have essentially the same information as the data in LSNa047.
Figure 2 gives an example of a “full” network. The network consists of the “anchor” of the network, eight persons and their relationships with anchor, and their mutual relationships. The respondent was asked cooperation for the Network Study, and if permission was obtained, the respondent was asked to give the full names and addresses of the selection of the network members. The existence of the relationships between network members was assumed (e.g. between anchor’s wife and anchor’s daughter) or was asked in the interview (e.g. between a daughter and a friend of the anchor) (see LSNa056). The nine persons (“points”) and the 22 relationships between them (“lines”) are referred to as the network, although it is a sampled part of the whole network when the anchor has more than eight network members. When we investigate the supportive exchanges in these 22 relationships, we have more data than is present in LSNa047: we have the supportive exchanges in a full network (we assume that non existing relationships have no supportive content). In this network, the respondent of the face-to-face survey has on the one hand the same position as the other network members, and, on the other hand, is the anchor of the network: the network is delineated by anchor. Furthermore, we have information about the content of each the relationships from two sources: for each relationship pair we have the answers of both participants in the relationship about the characteristics of the relationship.
Another way to present the network is with the help of an adjacency matrix (Table 1). The first column gives the names of the nine persons in the network, and the second gives a short description of the type of the relationship between the eight members and anchor. In the matrix in the right part of the table, the existence of a relationship is presented as 1 (equal to a line in figure 2), the absence of a relationship as 0, while the diagonal is empty.
Table 1. Adjacency matrix of the example network
|Mr. J. Jones||anchor||0||1||1||1||1||1||1||1||1|
|Mrs. A. Jones-Robertson||wife||1||1||1||1||1||1||0||1||1|
|Mr. B. Jones||son||2||1||1||1||1||1||0||0||1|
|Mrs. S. Jones||daughter||3||1||1||1||1||1||0||0||1|
|Mr. D. Jones||brother||4||1||1||1||1||0||0||0||1|
|Mr. R. Merchant||neighbor||5||1||1||1||1||0||0||0||0|
|Mrs. M. Flowers-Clark||colleague||6||1||0||0||0||0||0||0||0|
|Mr. P. Barnes||organization||7||1||1||0||0||0||0||0||0|
|Mrs. Y. Doll-Boot||friend||8||1||1||1||1||1||0||0||0|
All nine persons in this network received a questionnaire by mail. The anchor is asked to answer questions about his relationships with eight network members, his wife about seven relationships, and so on. In total in 1992-1993 we sent questionnaires to 4,264 respondents with 17,396 mutual relationships (Actually, half of these relationships exist, the other half concerns the mirrored relationship). There are at least three reasons to ask questions not only to the anchor, but to the network members too.
The first reason is that we are extremely interested in the circumstances of the people in the network. They are important if we are to understand why some elderly people give or receive so much support, and others so much less. If for example a friend gives a great deal of help, it might be because he is retired and has plenty of time to spare. If he also happens to live in the neighborhood, then he has all the more chance to give help and support. A daughter can be in a situation where she can not give much help at all, for example because she has a job and young children at home. If she also lives an hour drive away, it will be even harder for her to visit regularly and be much of a help. In the discussion now being conducted in society, a daughter is sometimes all too quickly assumed to be always able to help. We hope the data gathered here will provide a more discerning view of the options open for example to daughters to give help and support.
It is also important for us not to work from the assumption that it is always the older adult who needs help. This is why we persistently ask about the help and support the older adults give to the people in their network as well as the help and support they receive. We did this in the face-to-face interview as well as in the questionnaire we sent by mail.
We also posed a number of questions about what network members think about giving and receiving support. For example, how important they feel it is to give support. We asked if they felt it was only important to give help and support to their relatives, or also felt it was important to give help and support to their friends, whether male or female. We think people have different ideas about this, which might be relevant to the help and support that is given. It is clear that data about the ideas of the network members can not be gathered from the elderly respondents; we had to ask the people themselves.
A second reason to send network members a questionnaire is that we also want to know whether they know the other people in the network, and whether they ever help these other people. The pattern of giving and receiving help might be far more complicated than we tend to think. Most people are familiar with the following situation involving a son and daughter-in-law: “If I (daughter-in-law of the elderly respondent) get the housework finished now, then you (son of the elderly respondent) can go see your father.” We do not really know how often this occurs, or how often it is relevant to the help given to the elderly person, in this case the father. Barely any research has been conducted into this kind of pattern of indirect help from the daughter-in-law via the son to the father. Of course patterns of this kind do not only occur with an elderly person and his son and daughter-in-law. They can also occur in the relationships between an elderly person and various of his neighbors (see Figure 3). We are very curious as to whether we will be able to uncover information of this kind by way of this study.
A third reason to send questionnaires to the people in the networks is that each individual has his own idea of what happens in a personal relationship. If for example we ask how often one person helps another, a modest helper will be quick to say it isn’t that often, “I like doing it, and I am helping out a bit.” However, for the person who is on the receiving end, even the most modest amount of help might be extremely valuable. In that case, there is a chance that if we ask how much help was received, the amount might be overestimated. In a pilot study we conducted in 1991, there did indeed appear to be sizable differences between the amount of help one person reported giving and the amount the other person reported receiving (van Tilburg, 1992a). These findings confirm the results of an earlier study by Antonucci and Israel (1986). By comparing the information we got from the two persons, we are now better able to estimate how much help was “really” given. By comparing the responses given by the two persons, we hope to better understand the data gathered about the help given and received within personal relationships.
Furthermore, the availability of data from two sources (both persons in the relationship) makes it possible to compare the proxy data on demographic characteristics of network members as given by the anchor of the network and these data from the network members. This offers opportunities for methodological research into the reliability of survey data (see for examples Pfenning, Pfennig & Mohler, 1991; Schenk, Mohler & Pfennig, 1992).
2. Sample and Data Collection
The data collection was prepared during the face-to-face interviews we held with the elderly respondents in 1992. We asked them at the time whether they were willing to take part in this study. If that was the case, we asked them to provide the full names and addresses of a number of people in their network. These data were entered by the interviewer in the computer. When the data was presented to the people in charge of the study, all the information was checked. Typing errors were corrected, and the postal codes often had to be looked up. Then the questionnaires were drawn up. Each questionnaire is different, since each one contains the names of the various other people in the network. Checking the names and addresses was very time-consuming, as was producing the questionnaires (ever since April 1992, a printer has been producing them virtually day and night), and there was usually a period of a few months between the face-to-face interview and the moment when the questionnaires were sent out. In February 1993 we were finished sending out the questionnaires for the first observation (observation G). In May 1993 the second observation (H) began, and the third observation (I) started in June 1994 and finished in April 1995.
Respondents of the Main Survey
In 1992, face-to-face interviews were conducted with 4,494 respondents. In the Network Study, we confined ourselves to the 4,059 respondents who provided information about their relational network.
Questionnaire of the Main Survey
The networks of persons with whom the respondents maintained an important and frequent relationship were stipulated in the Main Study (Van Tilburg, 1995) by using a procedure based upon Cochran et al. (1990) (see LSNa047). The following seven categories were distinguished: people who live in the same household, children and children-in-law, other relatives, neighbors, people one is working or studying with, contacts in organizations, and other contacts (friends and acquaintances). In each of these categories, the respondents were asked to name people above the age of eighteen with whom they had important and regular contact. The size of the network was determined by the number of people who were named in the seven various categories.
A selected number of respondents (N= 1,547) were asked whether they were willing to provide the names and addresses of a maximum of eight of their network members (see LSNa055). The sample was to a certain extent stratified and consisted of more younger than older respondents, more unmarried, divorced and widowed respondents than respondents with a partner and respondents living in institutions, and more respondents with a low than a high ADL capacity. We asked: “As you know, this study focuses on the living situation and social ties of older adults. We have already asked you a number of questions about your situation, and more questions will follow. However, in order to obtain a more complete picture of your living situation and social ties, we would like to also put a number of questions to some of the people you just mentioned. More specifically, the following individuals: .. We would like to ask them about the composition of their families and about their daily activities. We would also like to ask a number of questions about their social ties. Our intention is to send them a questionnaire they can fill in at home. It takes less than 30 minutes to do so. Naturally, as is the case with the answers you have given, the information they provide will be treated confidentially, and will not be passed on to third parties. You will receive a questionnaire with roughly the same questions at the same time as they are approached. That questionnaire contains a number of questions that are different from the ones I am asking you today, and gives you an opportunity to be fully informed about what the next steps will be in this study. In the letter accompanying the questionnaire, we will mention that you have made it possible for us to contact them. Of course, it is up to them to decide for themselves whether or not they wish to respond. At this point I would like to ask you: Are you willing to participate in this part of the study? (Choice of answers: no; yes, under conditions; yes, no conditions).
The network members that were approached in the Network Study were the eight with the highest frequency of contact. If unconditional permission for all the addresses was obtained, the complete names and address of each selected network member were recorded. Otherwise, permission to obtain the name and address was requested for each selected network member separately. As a result of this procedure, 812 respondents refused to give permission to approach their network members, 326 respondents gave unconditional permission, and the others gave permission under the condition that only particular network members would be approached or said they would have to ask the network members’ permission individually. Furthermore, to be prepared for the Network Study, we wanted to know about which relationships between network members questions could be posed in the network questionnaire, and asked questions on the density of the network (see LSNa056): “Can you tell me which of these .. people are regularly in touch with one another without any involvement on your part? I will list pairs of names. You will notice, however, that not all the names will be listed. People who are related to each other are apt to keep in touch regularly without any involvement on your part. Is .. regularly in touch with ..?”
After this part of the questionnaire, the respondents were asked (see LSNa047) about the structural properties of the relationships or the network members (e.g. age, travel time, marital status, employment status) and about instrumental and emotional support received and given. Questions were posed only for the twelve or less relationships with the highest frequency of contact.
Respondents of the Network Study
After the data in the Main Study were received from the interviewers, the names and addresses of the network members mentioned were read from the diskettes, cleaned and stored in a database. If necessary, the respondents in the Main Study (anchors) were approached to ask whether they had received permission from their network members. Via this procedure, or by another report on the part of the anchors, 64 anchors refused to cooperate and 2 anchors who had refused at the time of the face-to-face interview said they were now willing to cooperate in the Network Study. This meant there were 673 anchors available for the Network Study. Besides these anchors, a selection of their network members served as respondents. The questionnaires were mailed between 15 and 349 days after the face-to-face interview (median 115 days), starting in April 1992. There were several reasons for the delay between the face-to-face interview and the mailing of the questionnaires, the most important of which was that the cleaning of the addresses, the second approach of the anchors by telephone or letter if more information was necessary, and the printing of the questionnaires were very time-consuming.
3. Response on the network level
Table 2 gives an overview of the willingness of the anchors to participate in the Network Study (see LSNghi055). Of the 1,547 respondents in the main survey, 812 refused (a cooperation of 48%; Schenk et al., 1992 reported for a comparable study 46% cooperation). By using logistic regression, we analyzed whether the anchors in the Network Study form a representative sample of the respondents in the principal sample (the Main Study). The analysis showed that the 812 respondents who refused to take part in the Network Study did not differ from the 735 respondents who – at the time of the face-to-face interview – were willing to cooperate with respect to sex (p= .37), partner status (no partner, living with a partner, partner outside the household) (p= .66), subjective health (p= .70), ADL capacity (p= .74) and network size (p= .11), but differed with respect to age (more younger people than older people were willing to cooperate, p= .004, odds ratio (OR)= .98).
Table 2. Overview of response of the Network Study at the level of the networks
|In face-to-face interview asked about network||4,059|
|Not eligible (network size=0)||15|
|Not asked for Network Study (sample)||2,497|
|Eligible for Network Study, assessed at T(x-1)||1,547||100||671||100||594||100|
|Refusal before questionnaires were mailed||64||4||39||6||27||5|
|Too little response T(x-1)||–||–||15||2||39||7|
|Not eligible T(x) (*2)||–||–||2||0||7||1|
1 At the time of the face-to-face interview, excluding two respondents who reported after the face-to-face interview that they were willing to cooperate, despite their refusal at the time of the face-to-face interview.
2 A variety of reasons, e.g. all network members have been deceased, severe illness of anchor, networks of two anchors (a couple) overlapped completely and were combined at T3.
Questionnaires were mailed to 671 anchors; two anchors deceased and 64 respondents who were willing to cooperate at the time of the face-to-face interview refused before the questionnaires were mailed. Another nineteen anchors and all of their network members did not return the questionnaires. We thus have at least partial information on 652 networks in the Network Study. A second logistic regression analysis showed that the 3,390 respondents who did not participate in the Network Study did not differ significantly from the 652 respondents who participated with respect to sex (fewer, but not significantly, females in the Network Study, p= .15, OR= .88), subjective health (p= .17, OR= .93), ADL capacity (p= .64, OR= .99), and network size (p= .55, OR= 1.00), but did differ in age (p= .000, OR= .96) and household composition / marital status (p= .000), with about the same proportion living with a partner, (p= .81, OR= .98), more people unmarried and living alone (p= .001, OR= 1.81), about the same proportion divorced and living alone (p= .64, OR= 1.10), about the same proportion widowed and living alone (p= .05, OR= 1.25), and institutionalized (p= .37, OR= .81).
We conclude that our realized sample is biased when we compare it with the Main Study, with the most important deviation for age. However, since the Main Study consists of a stratified sample according to sex and birth year, the realized sample of networks in the Network Study can be viewed as a probability sample.
Response on the level of network members
The selected network members of the remaining 671 respondents (the networks of the two deceased older adults were excluded) and the anchors themselves served as respondents in the Network Study. In the face-to-face interview, the 671 respondents in the Network Study mentioned a total of 4,679 network members who were eligible for the Network Study (the eight network members with the highest frequency of contact). The total number of network members (including anchor) was therefore 5,350 (see LSNghi002). However, when cooperation was requested for the Network Study or in the period between the face-to-face interview and the mailing of the questionnaires, permission to approach the network members was refused by anchor for 1,127 network members (see Table 3).
The decisions by the anchors on who to include in the Network Study were very selective with respect to frequency of contact and type of relationship, but not with respect to sex. By using logistic regression, we analyzed whether the network members (other than the anchors) in the Network Study differ from the network members the anchors mentioned in the face-to-face interview. The analysis (N= 4,651), based on data of the Main Study (LSNa047), shows that about an equal number of males and females were included (p= .03, OR= 1.17), more partners or spouses were included (p= .000, OR= 4.00), more children (p= .000, OR= 2.47), more children-in-law (p= .001, OR= 1.46), about an equal number of brothers of sisters (p= .62, OR= .94), and fewer brothers-in-law and sisters-in-law (p= .000, OR= .51), fewer other relatives (p= .001, OR= .67), fewer friends (p= .000, OR= .67) and fewer neighbors (p= .000, OR= .57); the average frequency of contact (in days per year) between the anchor and the network member was higher for those who were included than for those who were not (p= .01, OR= 1.0008).
For the first wave, 5,306 network members (including the anchors) were eligible. Questionnaires were sent only to network members for whom permission was not refused by anchor at the time of the preparation of the mailing. In addition to the network members for whom permission was refused by anchor at the time of the preparation of the mailing, after the delivery of the questionnaires the anchors refused for a number of network members. The response and non-response for the three waves is shown in Table 3. Note that the figures for the three waves in this table are based on a different number of networks (see Table 2 for an overview of response of the Network Study at the level of the networks).
The response, calculated as proportion of returned questionnaires on the number of questionnaires sent, in the Network Study at T1 was 75% (N= 4,264), and the response was higher for anchors (86%) than for other network members (72%). (We did not correct for the number of network members who were nominated ‘double’, that is by different respondents and for the number of network members who were respondents of the Main Study, as was done by Schenk et al. (1992). They reported a response rate of 66%.) For T2, the total response was 72% (anchors 78%, network members 71%), and for T3 the total response was 77% (anchors 81%, network members 76%). However, when we calculate the response rates as proportion of returned questionnaires on the number of eligible network members, lower percentages are found (60% for T1, 52% for T2, and 50% for T3). In this calculation is not taken into account that the number of network members differs across networks. We may take this into account by computing firstly the response rate for each network, and averaging secondly these percentages across the networks. The percentages are in that case 61% for T1, 53% for T2, and 51% for T3.
1 Including four network members who were not among the eight relationships with the highest frequency of contact; they were replacements for other network members.
2 E.g. deceased, ill or left network by movement (e.g. neighbor), retirement of anchor (colleague) or divorce (child in law); assessed at the time of the approach of the network members.
3 Network members other than kin of anchor who did not respond once and network members who did not respond twice were excluded for the next wave.
Response on the level of network relationships
For some analyses, e.g. full network analyses using software like UCINET (Borgatti, Everett & Freeman, 1992), the representativeness of the network data is determined by the number of relationships of which data is available. Table 4 shows the number of relationships available in the Network Study with data (collected from at least one of the two persons within the relationship), and the completeness of data within networks dependent of the criterium applied (see LSNghi055). For example, complete data at T1 are available for 233 networks when we limit our analyses to networks with 80% or more response.
Table 4. Network response (based on the number of relationships)
|N networks (*1)||670||592||500|
|M network members||7.9||7.8||7.8|
|Number relationships (*2)||23,300||19,865||16,507|
|Data available (*3)||14,912||10,961||8,603|
|% With data available||65.9||56.7||55.4|
|Number of networks available if we accept|
1 Non eligible networks excluded
2 These are the eligible relationships of the eight relationships with the highest contact frequency nominated in the Main Study
3 Item non-response may exist
When we compare the sex, age, partner status, subjective health, ADL capacities and network size of respondents of whom the network data are complete with the other respondents with network members, we find in logistic regression analyses for the 70%, 80% and 90% response categories only age to be significant (p< .01, OR about .96) and for the 100% response category age and network size significant (p< .01, both OR about .96). A complete response was more often realized in small networks than in large networks.
Conducting a full Network Study within the framework of a survey is characterized by several obstacles. It is not only a very time-consuming and expensive enterprise, but it is necessary to harm the privacy of anchors and their network members. As a consequence, the response rate is low. However, it is possible to select a relatively large number of networks of which (nearly) complete cross-sectional data are available, and which are representative for the networks of older adults in the Netherlands. For that, one has to select T1 networks with a high but not perfect response. The longitudinal data allows us to study changes within (a large number of) relationships and within (a small number of) networks.
5. Overview of the questionnaire
The mailed questionnaire (in English, in Dutch) included questions about demographic characteristics, living and working conditions, ADL capacity, problematic situations, loneliness, exchange orientation, and family features. As regards the relationships with their network members, questions were posed about contact frequency, activity intensity to maintain the contact, changes in contact frequency, the quality of a relationship as compared with other ones, travelling time and social support. The questionnaire was completely personalized. The names of network members were included in the list, and questions that were not relevant for certain members, such as travelling time where neighbors were concerned, were not posed.
Twelve questions were about the instrumental and emotional aspects of each relationship: six about support received and six about support given (see LSNghi047). Three of the six questions were about instrumental support and three about emotional support. The questions posed for receiving instrumental support were: “How often did it occur in the last year that the following persons helped you with daily household tasks (e.g. preparing meals, cleaning the house, transport, a chore)?”, “… gave you advice (e.g. on an important decision or on filling out forms)?”, and “… gave you help when you needed it, e.g. when you were ill?”, and for emotional support: “… gave you a present?”, “… showed you they cared for you?”, and “… that you told the following persons about your personal feelings?” (choice of answers: never, rarely, sometimes, often). The questions could be ranked on unidimensional scales of instrumental and emotional support received (at T1 H= .59 and .55, rho = .80 and .76, respectively) and given (at T1 H= .59 and .56, rho = .79 and .77, respectively) (see LSNghi247 for further information).
Four ADL items, the same as in the main survey, were used (see LSNghi030). They formed a hierarchically homogeneous scale (at T1 H= .77) which was reliably measured (at T1 rho = .92) (see LSNghi230 for further information). At T2 and T3, two items were added.
Overview of data files (see lsn-network-docu)
The data files of the NESTOR-LSN Network Study are stored in files with names beginning with LSNg for the first wave (1992-1993), LSNh for the second wave (1993-1994) and LSNi for the third wave (1994-1995). We refer to the collection of these files as the LSNghi-files. There are two data sources: the respondents (anchor and his/her network members) of the Network Study (N) and the system (S, e.g. computer system, administrative data, computations on original data).
|File||Source||Data about||ID variable||N|
|008||S||Realization of sample (response and non-response), sex, type of relationship||anwmem||4,264||3,754||3,162|
|230||S||Scale ADL capacity||anwmem||3,099||2,402||1,909|
|047||S||Characteristics of the relationship pairs||anwpair||17,396||15,131||12,637|
|047||N||Relationship characteristics and support||anwpair||12,887||9,788||7,720|
|247||S||Scales support exchanges||anwpair||12,739||9,687||7,539|
|055||S||Cooperation Network Study||respnr||4,059||670||594|
|075||N||Items communal and exchange orientation||anwmem||3,094||2,358||1,884|
|275||S||Scale exchange orientation||anwmem||3,030||2,302||1,855|
|083||N||Norms about support||anwmem||3,111||–||–|
|095||S||Geographic and financial data based on postal code||anwmem||4,264||3,754||3,162|
The identifiers of the cases in the LSNghi-files are RESPNR (the number of the respondent, i.e. the anchor of the network), ANWMEM (the first five figures are the respondent number, followed by a unique number in the sequence in which the network members were referred to; the last two figures are 00 for anchors) and ANWPAIR (the first five figures are the respondent number, followed by a unique number given twice in the sequence in which the network members were referred to). The identifiers are similar to the identifiers in the LSNa-files.
- Antonucci, T.C., & Israel, B.A. (1986). Veridicality of social support: A comparison of principal and network members’ responses. Journal of Consulting and Clinical Psychology, 54, 432-437.
- Borgatti, S.P., Everett, M.G., & Freeman, L.C. (1992). UCINET IV version 1.00. Columbia: Analytic Technologies.
- Pfennig, A., Pfennig, U., & Mohler, P.P. (1991). Zur Realiabilitt von egozentrierten Netzwerken in Massenumfragen [Reliability of ego centered networks in surveys]. ZUMA Nachrichten, 15, 92-93.
- Schenk, M., Mohler, P.P., & Pfenning, U. (1992). Egozentrierte Netzwerke in der Forschungspraxis: Ausschöpfungsquoten und Validität soziodemographischer Variablen [Ego centered networks in research practice]. ZUMA Nachrichten, 16, 87-120.
- van Tilburg, T.G. (1992a). Question sequence effects in the measurement of reciprocity. Quality and Quantity, 26, 395-408.
- van Tilburg, T.G. (1995). Delineation of the social network and differences in network size. In C.P.M. Knipscheer, J. de Jong Gierveld, T.G. van Tilburg & P.A. Dykstra (Eds.), Living arrangements and social networks of older adults (pp. 83-96). Amsterdam: VU University Press.
Publications using data from the Network Study
- Klein Ikkink, C.E. (2000). If I scratch your back …? Reciprocity and social support exchanges in personal relationships of older adults. PhD Dissertation, Vrije Universiteit Amsterdam.
- Klein Ikkink, C.E., & van Tilburg, T.G. (1998). Do older adults’ network members continue to provide instrumental support in unbalanced relationships? Journal of Personal and Social Relationships, 15, 59-75.
- Klein Ikkink, C.E., van Tilburg, T.G., & Knipscheer, C.P.M. (1999). Perceived instrumental support exchanges in relationships between elderly parents and their adult children: Normative and structural explanations. Journal of Marriage and the Family, 61, 831-844.
- Klein Ikkink, C.E., van Tilburg, T.G., & Broese van Groenou, M.I. (1995). Strategieën bij wederkerigheid in onderlinge steun. In B.C.M. Nitsche (Ed.), Ouderen, wetenschap en beleid II (pp. 79-96). Utrecht: NIG.
- Knipscheer, C.P.M., & Van Tilburg, T.G. (2003). Family characteristics and loneliness among older parents. In V.L. Bengtson & A. Lowenstein (Eds.), Global aging and challenges to families (pp. 143-158). Hawthorne, NY: Aldine de Gruyter.