INTRODUCTION
1 This publication presents results from a supplementary survey run in association with the March 2004 Monthly Population Survey.
METHODOLOGY
Monthly Population Survey
2 The Monthly Population Survey is based on a multi-stage area sample of private dwellings (houses, flats, etc.) and a list sample of non-private dwellings (hotels, motels, etc.). The sample for a monthly population survey is approximately 30,000 dwellings, however, this would equate to approximately 15,000 dwellings for the March suppementary topic as this was run on a half cluster only (i.e. only half the sample for March 2004). Information was obtained by interviews with responsible adult members of selected households, who answered questions on behalf of the person whose next birthday was closest to the date of the interview. Interviews are conducted face-to-face or by telephone (if acceptable to the respondent). The information obtained relates to the week before the interview (i.e. the reference week).
3 Information is collected using computer assisted interviewing (CAI), whereby responses are recorded directly onto an electronic questionnaire on a notebook computer. The CAI method was progressively implemented from October 2003 to August 2004, replacing the 'pen and paper ' method previously used. CAI for March 2004, as part of the phase-in strategy, was 10% across Australia, with an additional 30% in some states.
SCOPE
4 The survey covers rural and urban areas across all states and territories of Australia, however the Northern Territory data refers to mainly urban areas. Also excluded were some 175,000 persons living in remote and sparsely settled parts of Australia. The exclusion of these persons will 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 such persons account for over 20% of the population.
5 Persons aged 18 years and over who were usual residents of private dwellings were included in the surveys except:
- members of the Australian permanent defence forces;
- certain diplomatic personnel of overseas governments, customarily excluded from censuses and surveys;
- overseas residents in Australia;
- members of non-Australian defence forces (and their dependents) stationed in Australia; and
- residents of other non-private dwellings such as hospitals, motels and gaols.
COVERAGE
6 Coverage rules were applied which aimed to ensure that each person was associated with only one dwelling, and hence had only one chance of selection in each survey.
DATA COMPARABILITY
7 A set of changing topics rotate over a period of three years. The topics contained in this publication compare with some data collected in 1992, 1994, 1996, 1998, and 2001. Where applicable, the data have been included in this publication for comparison purposes.
8 An important point to note is that the environment topics were surveyed using a 'personal interview' methodology before 1997. From 1997 onwards the 'any responsible adult' methodology has been applied. When comparing post-1997 and pre-1997 data readers should be aware that some differences in the data may be explained by the change in methodology rather than real changes over time.
RELIABILITY OF ESTIMATES
9 The two types of error possible in an estimate based on a sample survey are:
- Non-sampling error which arises from inaccuracies in collecting, recording and processing the data. The most significant of these errors are:
- misreporting of data items
- deficiencies in coverage
- non-response
- processing errors
Every effort is made to minimise these errors by the careful design of questionnaires, intensive training and supervision of interviewers and efficient data processing procedures.
- Sampling error which occurs because a sample, rather than the entire population is surveyed. One measure of the likely difference resulting from not including all persons in the survey is given by the standard error (please consult the Technical note).
RELATED PUBLICATIONS
10 Users may also wish to refer to the following publications: Environmental Issues: People's Views and Practices (cat.no.4602.0) - 1992-2003 issues; and Water Account Australia (cat. no. 4610.0).
11 Further key references on environmental concerns, water use and conservation, environmentally friendly products and protected areas can be found through the following websites:
12 Current publications produced by the ABS are listed in the Catalogue of Publications and Products (cat.no.1101.0) also available from this website.The ABS also issues a daily Release Advice on the website which details products to be released in the week ahead.