Input coding is the process by which certain data items were categorised during the interview. In the 2011-12 NHS and NNPAS, these included:
- ancestry (NHS only)
- country of birth of respondent and their parents
- main language spoken at home
- industry and industry sector
- educational qualification
- relationship within a household.
Interviewers were able to code from a list of commonly used options (for example, 10 common languages spoken at home) or from a more comprehensive list contained within a 'trigram coder' (which allowed the interviewer to enter the first three letters of a response, then select the appropriate response from a pick list of options).
An outline of the input coding undertaken follows:
- Ancestry (NHS only) - the survey questionnaire asked the respondent what their ancestry was and allowed them to choose up to two ancestries. Interviewers were provided with a list of 7 frequently reported ancestries to select from. If the reported ancestry was not within this list, the interviewer entered the first three letters of the ancestry and selected the appropriate response from a comprehensive list contained within the trigram coder. If the respondent indicated they had a second ancestry the process was repeated. Ancestries contained with the trigram coder were from the Australian Standard Classification of Cultural and Ethnic Groups (ASCCEG), 2005-06 (cat no. 1249.0).
- Country of birth of respondent and their parents - respondents were asked in which country they were born, as well as their father and mother. For these questions interviewers selected from a list of 10 frequently reported countries or from a trigram coder. Countries contained within the trigram coder were from the Standard Australian Classification of Countries (SACC), Revision 2.03, 2007 (cat. no. 1269.0).
- Main language spoken at home - interviewers selected from a list of 10 frequently reported languages spoken at home or from a trigram coder. Languages contained within the trigram coder were from the Australian Standard Classification of Languages (ASCL), 2005-06 (cat. no. 1267.0). More detail regarding this classification is contained in Appendix 3: ABS Standard Classifications.
- Occupation - occupation relates to the main job held by employed respondents at the time of interview. Occupation was office coded, based on a description of the kind of work performed, as reported by respondents. Occupation was coded to the Australian and New Zealand Standard Classification of Occupations (ANZSCO), 2007 (cat. no. 1220.0).
- Industry and industry sector - these relate to the main job held by employed respondents at the time of interview. These were office coded based on the name of employer and the respondent's description of the business or service carried out at the respondent's workplace. Industry was coded to the Australian and New Zealand Standard Industrial Classification (ANZSIC), 2006 (cat. no. 1292.0).
- Educational qualification - level of highest non-school educational qualification and field of study of that qualification were coded to the Australian Standard Classification of Education (ASCED), 2001 (cat. no. 1272.0). In the NHS, level and field of current study were also coded to the ASCED 2001.
- Relationship within a household - collected from a responsible adult in the household at commencement of the interviews. They provide basic information about all persons who live in the household. Household composition, family composition and other relationship variables are then produced either via derivations within the instrument, or via office coding.
More detail regarding use of these classifications, except relationship in household, is contained in Appendix 3: ABS Standard Classifications.