Using secondary data JN602 Week 06 Sources and Reading: Veal Chapter 5 SLT Chapter 7
Lecture outline • Primary versus secondary data • Types of secondary data • Sources of secondary data • Evaluation of data quality • Reliability & Validity
Primary vs Secondary data (Veal, 2005) • Primary data: • new data specifically collected in current research project • researcher is the primary user. • Secondary data: • data already exist - collected for some other (primary) purpose • researcher is the secondary user. • Secondary dataanalysis: Chapter 12
Uses/roles of secondary data • Background/preparation • Complementary – comparison/validation of primary data collected • Whole basis of project – re-analysis of data • Context setting (in report)
Use of Secondary Analysis • Economics • Accounting • Political Science • Geography • History
Advantages of Secondary Data(SLT, 2003, Section 7.4) • Fewer resource requirements • Unobtrusive • Often longitudinal • Means of comparison with primary data • Can provide contextual data • Can result in unforeseen discoveries • Permanence of data – often stored in archives
Disadvantages • Collected for an alternate purpose • May not match your own • Difficulty of access • Expense • Degree of aggregation • Data quality
Types of Secondary Data • Data already collected for some other purpose SLT Figure 7.1
Documentary • Written: • Organisation documents: personnel records, safety audits • Reports: company, government bodies, committees • Public documents: books, journals, newspapers • Non-written: • Television and radio • Video and audio tapes
Company/Organisation data: INTERNAL • Financial accounts • Sales data • Prices • Product development • Advertising expenditure • Purchase of supplies • Human resources records • Customer complaint logs
Company/Organisation data: EXTERNAL • Company information is available from a variety of sources, eg.: • Biz@advantage • www.whowhere.com • www.hoovers.com – 12,000 companies, USA & others • Australian Stock Exchange (www.asx.com.au) • AGSM Annual reports • Kompass, Dun & Bradstreet (www.dnb.com), Fortune 500
Possible documentary data? • Journals and books • Case study materials • Committee minutes • AIRC documentation • Hansard transcripts • Mailing list discussions • Web-site content • Advertising banners
Multiple Source(SLT, 2003) • Geographically-based • FT and IMF country reports • ABS Basic Community Profiles • Time-series based • Industry statistics and reports • Employer associations (ACCI, VECCI, AIG) • Government publications • Australian Bureau of Statistics • Bureau of Labor Statistics (U.S.A.)
ABS Subject/Area codes Subject Geographical areas • 1 General 0 Australia • 2 Census of population and housing 1 New South Wales • 3 Demography 2 Victoria • 4 Social statistics 3 Queensland • 5 National accounts, international trade & finance 4 South Australia • 6 Labour statistics and prices 5 Western Australia • 7 Agriculture 6 Tasmania • 8 Secondary industry and distribution 7 Northern Territory • 9 Transport, tourism 8 Aust. Capital Territory 9 External Territories Examples of publications and code numbers: • 6356.0 Employer Training Practices, Australia • 8141.0 Small & Medium Enterprises Business Growth & Performance Survey Australia • 6201.1 Labour Force, NSW
Censuses • Australia • 2001 Census data • http://www.abs.gov.au • International • New Zealand: http://www.stats.govt.nz/ • U.S.A.: http://www.stats-usa.gov • IPUMSI: http://www.hist.umn.edu/~rmccaa/IPUMSI/
On-going and recurring surveys • Australian Bureau of Statistics • http://www.abs.gov.au • Reserve Bank of Australia • http://www.rba.gov.au/Statistics/ • Statistics New Zealand • http://www.stats.govt.nz/ • The World Bank • http://www.worldbank.org/data/
Ad-hoc surveys • Social Science Data Archive (ANU) • http://ssda.anu.edu.au • The Data Archive (Uni. of Essex, UK) • http://www.data-archive.ac.uk/ • Interuniversity Consortium for Political and Social Research • http://www.icpsr.umich.edu • Qualitdata • http://qualidata.essex.ac.uk/
Secondary Data Sets • Longitudinal Survey of Australian Youth • Australian Centre for Educational Research • 1989 – Present • Progress from 15 through to post university • Business Longitudinal Survey • 5100 Australian small-to-medium enterprises • 5 year (1994-98 panel study conducted by ABS • World Values Survey • 60 countries, every 5 years (approx.) • Attitudes towards various social, economic and political issues
Considerations with Secondary Data • Suitability • Intended for another purpose • Content versus external validity • Reliability • Measurement bias • Original research methodology • Cost • Time
Example Research Problem • What distinguishes individuals who join trade unions from those who do not? • What distinguishes individuals who leave trade unions from those who do not? • Four possibilities:
Core research issues • Union instrumentality and ideology • Work context • Life context • Economic situation • Family history • Related attitudes
Choice of Data • Australian Workplace Industrial Relations Survey • 19000 employees in 2000 workplaces • National Social Science Survey • 1200 respondents in both 1990 and 1996 • Makes it possible to assess change over time • Account for differences in: Work, Family, Income, Location, Attitudes
Advantages of secondary data • Time • Economy • Generally inexpensive in comparison to collecting one's own data • High initial cost: AWIRS 1995 budget of $3 mil. • Savings from re-use and re-cycling • Often free for academic researchers or can be acquired for tens or hundreds of dollars • E.g. post-graduate students are typically precluded from collecting national samples because of cost.
Methodological Advantages • Large-scale, representative samples: • Longitudinal, broad geographical • Strong on external validity (the degree of confidence with which findings about a sample can be generalised to a population) • Often generated by well resourced teams that have access to specialists • For example, high level sample design expertise • Does not normally require approval from ethics committees
Goodness of Measures • Reliability • A matter of whether a particular technique, applied repeatedly to the same object, yields the same result each time. • How stable and consistent is the measuring instrument? • Validity • The extent to which an empirical measure adequately reflects the real meaning of the concept under consideration. • Are we measuring the right thing?
Reliability • Stability • refers to the ability of a measure to maintain consistency over time, despite uncontrollable testing conditions or the state of the respondents themselves • Internal consistency • indicates how well the items ‘hang together as a set’ and can independently measure the same concept, so respondents attach the same overall meaning to each of the items
Forms of validity • Face validity • That quality of an indicator that makes it seem a reasonable measure of a variable. • Criterion related validity • The degree to which a measure relates to some external criterion. For example, the validity of the VCE tests is shown in their ability to predict the college success of students.
Forms of validity (cont.) • Construct validity • The degree to which a measure relates to other variables as expected within a system of theoretical relationships. • Content validity • Refers to how much a measure covers the range of meanings included within a concept.
Evaluating potential secondary data sources • Assess overall suitability of data to research question(s) and objectives • Measurement validity, coverage • Evaluate precise suitability of data for analyses needed to answer research question(s) and to meet objectives • Validity, reliability, measurement bias • Judge whether to use data based on an assessment of costs and benefits in comparison with alternative sources If you consider the data are definitely unsuitable DO NOT proceed beyond this stage
Unions - Content validity • Includes various measures of • Job satisfaction • Atittudes towards trade unions • Perceptions of class • Employment situation • Related attitudes • No direct measure of “union instrumentality” • Need to use proxy: work instrumentality
Conclusions • Secondary data can save time, money and effort • However, it needs to be carefully assessed for suitability • Be sure to check the research methodology used to collect the data
Sources • Veal (2005) Chapter 5 • Saunders, Lewis and Thornhill (2003), Chapter 7