EXPLANATORY NOTES


INTRODUCTION

1 The statistics in this publication were compiled from data collected in the Multi-Purpose Household Survey (MPHS), which was conducted throughout Australia in the 2009-10 financial year as a supplement to the Monthly Population Survey (MPS). The MPHS is designed to provide statistics annually for labour, social and economic topics.

2 The topics collected in the 2009-10 MPHS, in addition to household and person socio-demographic characteristics, were:

• Family Characteristics
• Attendance at selected cultural venues and events
• Sports attendance
• Participation in sport and physical recreation
• Work related injuries
• Crime victimisation
• Patient experience

3 For all topics, information on labour force characteristics, education, income and other demographics are also available.

4 Data from the Family Characteristics topic are presented in this publication. Data for other MPHS topics collected in 2009-10 will be released in separate publications.

5 The Family Characteristics topic has been collected before, in 1982, 1992, 1997, 2003 and in 2006-07. A full list of data items available for the FCS is available from the ABS website <www.abs.gov.au>.

6 The publication Labour Force, Australia (cat. no. 6202.0) contains information about survey and sample design, scope, coverage and population benchmarks relevant to the MPS, and consequently the MPHS. This publication contains definitions of demographic and labour force characteristics, and information about telephone interviewing.


SCOPE

7 The scope of the 2009-10 Family Characteristics Survey (FCS) included all usual residents in private dwellings, except:

• diplomatic personnel of overseas governments, and their dependants, excluded from censuses and surveys of Australian residents
• members of non-Australian defence forces stationed in Australia, and their dependants
• persons living in non-private dwellings such as hotels, university residences, students at boarding schools, patients in hospitals, residents of homes (e.g. retirement homes, homes for persons with disabilities, women's shelters), and inmates of prisons.

8 The survey was conducted in both urban and rural areas in all states and territories, but excluded people living in very remote parts of Australia. This is expected to have only a minor impact on any aggregate estimates that are produced for individual states and territories, with the exception of the Northern Territory where people living in very remote areas account for around 24% of the population.


COVERAGE

9 Coverage rules are applied to ensure that each person is associated with only one dwelling and hence has only one chance of selection in the survey. See Labour Force, Australia (cat. no. 6202.0) for more details.


DATA COLLECTION

10 ABS interviewers conducted personal interviews by either telephone or at selected dwellings, from July 2009 to June 2010. Each month a sample of dwellings were selected for the MPHS from the responding households in the last rotation group for the MPS. In these dwellings, after the MPS had been fully completed for each person, a usual resident aged 15 years and over was selected at random and asked the additional MPHS questions in a personal interview. Information was collected using Computer Assisted Interviewing (CAI), whereby responses are recorded directly onto an electronic questionnaire in a notebook computer.

11 The FCS collected information from the randomly selected person about the household and about every person in the household, including all children in the household. There were 35,700 person records for the survey.

12 Where the randomly selected respondent was aged 15-17 years, and a parent/guardian or other responsible adult aged 18 years and over was resident in the household, permission was sought from the parent or other adult to interview the young person. Regardless of whether permission was granted, details for Family Characteristics and household income (excluding the income of the selected person) were collected from the parent or other adult.

13 The survey collected information about parent-child relationships beyond the usual residence of the child. The survey collected information about resident children aged 0-17 years in the household who had a natural parent living in another household. In addition, the survey identified whether respondents were parents who had natural children aged 0-17 years living elsewhere with the child's other natural parent.


WEIGHTING, BENCHMARKING AND ESTIMATION

Weighting

14 Weighting is the process of adjusting results from a sample survey to infer results for the total in-scope population. To do this, a 'weight' is allocated to each covered sample unit (i.e. a person, a family or a household). The weight is a value which indicates how many population units are represented by the sample unit.

15 The first step in calculating weights for each unit is to assign an initial weight, which is the inverse of the probability of being selected in the survey. For example, if the probability of a person being selected in the survey was 1 in 600, then the person would have an initial weight of 600 (that is, they represent 600 people).


Benchmarking

16 The initial weights were calibrated to align with independent estimates of the population of interest, referred to as 'benchmarks' in designated categories of sex by age by state or territory and part of state or territory. Weights calibrated against population benchmarks ensure that the survey estimates conform to the independently estimated distribution of the population rather than to the distribution within the sample itself. Calibration to population benchmarks helps to compensate for over or under-enumeration of particular groups of persons which may occur due to either the random nature of sampling or non-response.

17 The 2009-10 Family Characteristics data were benchmarked to the Estimated Resident Population (ERP) in each state and territory, excluding the ERP living in very remote areas of Australia, at 31st March 2010. The ERP estimates were based on results from the 2006 Census of Population and Housing. Therefore the estimates from this survey do not (and are not intended to) match estimates for the total Australian resident population (which include persons and households living in non-private dwellings, such as hotels and boarding houses, and in very remote parts of Australia) from other ABS sources.

18 The survey estimates conform to person benchmarks by State, part-of-State, age and sex, and to household benchmarks by State, part-of-State and household composition (number of adults and children usually resident in the household). These benchmark variables are the same as those used in the 1997, 2003 and 2006-07 Family Characteristics surveys. The only change has been in relation to age groups for which some collapsing was required for each collection. The impact of this change on estimates not involving age is minimal.


Estimation

19 Survey estimates (e.g. counts of persons, families or households) are obtained by summing the relevant weight (for persons, families or households) with the characteristic of interest.


RELIABILITY OF ESTIMATES

20 All sample surveys are subject to error which can be broadly categorised as either sampling error or non-sampling error. Sampling error occurs because only a small proportion of the total population is used to produce estimates that represent the whole population. Sampling error can be reliably measured as it is calculated based on the scientific methods used to design surveys. Non-sampling errors occur when survey processes work less effectively than intended. For example, some persons selected for the survey may not respond (non-response); some survey questions may not be clearly understood by the respondent; and occasionally errors can be made in processing data from the survey.


Sampling error

21 Sampling error is the difference between the published estimates, derived from a sample of persons, and the value that would have been produced if all persons in scope of the survey had been included. Sampling error is measured for this survey by relative standard errors (RSEs). For more information refer to the Technical Note.


Non-sampling error

22 One of the main sources of non-sampling error is non-response by persons selected in the survey. Non-response can affect the reliability of results and can introduce bias. The magnitude of any bias depends upon the level of non-response and the extent of the difference between the characteristics of those people who responded to the survey and those who did not.

23 To reduce the level and impact of non-response, the following methods were adopted in this survey:

• face-to-face interviews with some respondents who were not available for telephone interview
• the use of interviewers who could speak languages other than English where necessary
• follow-up of respondents if there was initially no response
• ensuring the weighted file is representative of the population by aligning the estimates with population benchmarks.

24 Every effort was made to minimise other non-sampling error by careful design and testing of questionnaires, intensive training and supervision of interviewers, and extensive editing and quality control procedures at all stages of data processing.

25 An advantage of the CAI technology used in conducting interviews for this survey is that it potentially reduces non-sampling errors by enabling edits to be applied as the data are being collected. The interviewer is alerted immediately if information entered into the computer is either outside the permitted range for that question, or contradictory to information previously recorded during the interview. These edits allow the interviewer to query respondents and resolve issues during the interview. CAI sequencing of questions is also automated such that respondents are asked only relevant questions and only in the appropriate sequence, eliminating interviewer sequencing errors.


HISTORICAL COMPARISONS

26 Family Surveys were conducted by the ABS in 1982 and 1992, and the Family Characteristics Survey (FCS) was previously conducted in 1997, 2003 and 2006-07. The Family Surveys, and to a lesser extent the 1997 FCS, differed from the 2003 and 2006-07 FCS in some areas. Nevertheless, these differences do not preclude useful comparisons between them for certain data items. Some data from the 1997, 2003 and 2006-07 surveys have been included in this publication to show changes over time.

27 Changes listed below were made to the content of the FCS between 1997 and 2003, and between 2003, 2006-07 and 2009-10. These changes should be noted when making comparisons over time.

• Information was collected in 1997 and 2003 for children who did not live with either natural parent (e.g. grandchildren, otherwise related and unrelated children), about whether they had a natural parent living elsewhere. In 2006-07 and 2009-10, this information was not obtained for those children who were adopted, or for those for whom the relationship to either parent was unknown.
• In 2003, 2006-07 and 2009-10 the definition of step families includes families where there were children who were the natural child of one parent, and otherwise related or unrelated to the other parent. In 1997, step families were defined only where children were reported as step children.
• The 2003 FCS collected detailed information for up to three children aged 0-17 years in a family. In families with four or more children aged 0-17 years, only limited information (age, sex and relationship to parents) was collected for the fourth and subsequent children, up to a maximum of nine children. The remaining details for these children were imputed from information already collected for the first three children. In 2006-07 and 2009-10, these details were collected for all children in the household (i.e. there was no upper limit on the number of children about which information was directly collected).
• Child support data collected in 2003 was not collected in 2006-07. Due to major reforms to the Child Support Scheme, the child support component, last collected in 2003, was updated for 2009-10 to collect more information about child support arrangements for resident children. The 2009-10 FCS also collected new information about child support and visitation relating to non-resident children, and visiting patterns of resident children with grandparents.
• There have been some changes between 2003, 2006-07 and 2009-10 in collection and processing methods for data relating to children aged 0-17 years who had a natural parent living elsewhere, in particular for data on contact arrangements with the other parent. In 2006-07 there were approximately 74,000 cases and in 2009 -10 approximately 81,000 cases where contact arrangements with the parent living elsewhere were not known. Those data have been excluded from the detailed 'Frequency of contact' and 'Proportion of nights' data in the contact arrangements publication tables, although these children contribute to the total (footnotes are included in the relevant tables). There were no cases in 1997 and 2003 where contact arrangements with the parent living elsewhere were not known.
• There has also been changes in the calculation of the number of overnight stays per year with their non-resident parent by children aged 0-17 years. In 2003 adjustments were made to the reported data where the child stayed 50% or more nights with the non-resident parent. This adjustment affected published proportions for 30-49% and 50% or more. No such adjustments have been made to reporting in 2006-07 and 2009-10. This difference in approach has meant that there is a higher number of children in 2006-07 and 2009-10 reported as staying 50% or more nights with the non-resident parent. These changes may not reflect a real world change, and constitute a break in series.
• Additional information was collected in 2006-07 and 2009-10 about whether persons aged 18 years and over have any natural children aged 0-17 years living elsewhere, but not with the other natural parent.

FAMILY CODING PRACTICES

28 Data items such as 'family composition' in household surveys are based on initial information gathered about the members of the household and their relationships to each other. Family coding is the process of allocating household members to families, where appropriate, based on their spousal, parent-child, and other familial relationships to other members of the household. All children aged 0-14 years are assigned a parent or nominal parent, for example a grandchild living with only his/her grandparents will have the grandparents allocated as nominal parents.

29 The family topics in the 2006-07 FCTS and 2009-10 FCS are designed to capture more accurate information about the composition of families than that collected in other ABS surveys. In 2006-07 and 2009-10, as was the case in 2003, a number of populations and data items have been modified to more accurately classify persons and families where there was a parent/guardian and child/ward relationship. Prior to the 2003 FCS, children aged 15-17 years whose relationship fell outside the standard parent-child classifications (e.g. grandchildren living with grandparents, children living with other related or unrelated adults in a guardian-ward relationship) were classified as 'other related individuals' or 'unrelated individuals'.

30 For example, in the 1997 FCS a 15-17 year old child living with his or her grandparents would have resulted in the grandparents being coded to 'couple family without children' and the child would be an 'other related individual'. For the 2003, 2006-07 and 2009-10 surveys, the family classification allows for inclusion of people with this relationship in the same family. For the example outlined above, the family would be classified as a 'couple family with children'.


FUTURE SURVEYS

31 The ABS plans to repeat the Family Characteristics topic three yearly as part of MPHS. It will next be collected in 2012-13, along with the Family Transitions and History topic which is collected 6 yearly.


ACKNOWLEDGMENT

32 ABS surveys draw extensively on information provided by individuals, businesses, governments and other organisations. Their continued cooperation is very much appreciated. Without it, the wide range of statistics published by the ABS would not be available. Information received by the ABS is treated in strict confidence as required by the Census and Statistics Act 1905.


PRODUCTS AND SERVICES

Publication data cubes

33 Data cubes of all tables related to this publication in Excel spreadsheet format can be found on the ABS website (from the download tab of this publication). The spreadsheets present tables of estimates, proportions and the corresponding relative standard errors (RSEs).


Data item list

34 A full list of data items is also available from the ABS website (see the Downloads tab for cat. no. 4442.0).


State/territory tabulations

35 Selected tables at the state and territory level will be available for download as Excel spreadsheets from the ABS website. These tables will be customised depending on the size of the sampling error.


Microdata

36 For users who wish to undertake more detailed analysis of the survey data, microdata will be available in the form of a confidentialised unit record file (CURF) (cat. no. 4442.0.55.001). The CURF will only be available via the Remote Access Data Laboratory (RADL), which is a secure Internet-based data query service. Technical information describing the content and use of the CURF will be available in a Technical Manual (cat. no. 4442.0.55.002).

37 A full range of up-to-date information about the availability of ABS CURFs and about applying for access to CURFs is available via the ABS website (see Services, Confidentialised Unit Record Files). Inquiries to the ABS Microdata Access Strategies Section should be made by e-mail: microdata.access@abs.gov.au, or telephone (02) 6252 7714.


Special data services

38 The ABS offers specialist consultancy services to assist clients with more complex statistical information needs. Clients may wish to have the unit record data analysed according to their own needs, or require tailored tables incorporating data items and populations as requested by them. Tables and other analytical outputs can be made available electronically or in printed form. However, as the level of detail or disaggregation increases with detailed requests, the number of contributors to data cells decreases. This may result in some requested information not being able to be released due to confidentiality or sampling variability constraints. All specialist consultancy services attract a service charge, and clients will be provided with a quote before information is supplied. For further information, contact the National Information and Referral Service on 1300 135 070.