TECHNICAL NOTE DATA QUALITY
RELIABILITY OF THE DATA
1 The estimates in this release are based on information obtained from the 2011-12 Film, Television and Digital Games Survey, which relied in part on a sample survey design. Any collection of data may encounter factors that impact the reliability of the resulting statistics, regardless of the methodology used. These factors result in non-sampling error. In addition to non-sampling error, sample surveys are also subject to inaccuracies that arise from selecting a sample rather than conducting a census. This type of error is called sampling error.
2 Data for this publication was obtained using different selection methods obtained from a randomly selected, stratified sample of Film and video production and post-production businesses and also a census of two other populations: Broadcasters and channel providers, and Digital game developers. Consequently, estimates for Film and video production and post-production businesses are subject to sampling variability, that is, they may differ from the figures that would have been produced if the data had been obtained from all businesses in the population. One measure of the likely difference is given by the standard error, which indicates the extent to which an estimate might have varied by chance because only a sample of units was included. There are about two chances in three that a sample estimate will differ by less than one standard error from the figure that would have been obtained if a census was conducted and approximately 19 chances in 20 that the difference will be less than two standard errors.
3 Estimates related to the Broadcasters and channel providers population and Digital game developers population were based on a census of these businesses, and hence are not subject to sampling error.
4 Estimates of production activity for film, television and video are drawn from both the sample of Film and video production and post-production businesses, and also the census of Broadcasters and channel providers. Hence these estimates are also subject to sampling variability.
5 Sampling variability can also be measured by the relative standard error (RSE), which is obtained by expressing the standard error as a percentage of the estimate to which it refers. The RSE is a useful measure in that it provides an immediate indication of the percentage errors likely to have occurred due to the effects of random sampling, and this avoids the need to refer also to the size of the estimate. The table below contains estimates of RSEs for a selection of the statistics presented in this publication.
6 The size of the RSE may be a misleading indicator of the reliability of the estimates for (a) operating profit before tax, (b) operating profit margin and (c) industry value added. It is possible for an estimate legitimately to include positive and negative values, reflecting the financial performance of individual businesses. In this case, the aggregated estimate can be small relative to the contribution of individual businesses, resulting in a standard error which is large relative to the estimate.
RELATIVE STANDARD ERRORS, Film, television and digital games(a)
Film and video production and post-production businesses
Broadcasters and channel providers
Digital game developers
Film and video production businesses
Film and video post-production businesses
|Total employment |
|Total income |
|Total expenses |
|Industry value added |
|- nil or rounded to zero (including null cells) |
|(a) For scope and coverage details, see Explanatory Notes, paragraphs 6-28. |
To illustrate, an estimate of total income for Film and video production businesses
was $2,194.2m. The RSE was estimated to be 4.3%, giving a standard error of approximately $94.4m. Therefore, there are two chances in three that, if all units had been included in the survey, a figure in the range of $2,099.8m to $2,288.6m would have been obtained, and 19 chances in 20 (i.e. a confidence interval of 95%) that the figure would have been in the range of $2,005.5m to $2,382.9m.
The sampling variability for estimates at the state/territory level was generally higher than for Australian level aggregates. Survey estimates for states/territories should therefore be viewed with more caution than national estimates.
Errors other than those due to sampling may occur in any type of collection, whether a full census or a sample, and are referred to as non-sampling errors. All data presented in this publication are subject to non-sampling error. Non-sampling error can arise from inadequacies in available sources from which the population frame was compiled, imperfections in reporting by providers, errors made in collection, such as in recording and coding data, and errors made in processing data. It also occurs when information cannot be obtained from all businesses selected. The imprecision due to non-sampling variability cannot be quantified and should not be confused with sampling variability, which is measured by the standard error.
Although it is not possible to quantify non-sampling error, every effort is made to minimise it. Collection forms are designed to be easy to complete and assist businesses to report accurately. Efficient and effective operating procedures and systems are used to compile the statistics. The ABS compares data from different ABS (and non-ABS) sources relating to the one industry, to ensure consistency and coherence.
Differences in accounting policy and practices across businesses and industries can also lead to some inconsistencies in the data used to compile the estimates. Although much of the accounting process is subject to standards, there remains a great deal of flexibility available to individual businesses in the accounting policies and practices they adopt.
The above limitations are not meant to imply that analysis based on these data should be avoided, only that the limitations should be considered when interpreting the data. This publication presents a wide range of data that can be used to analyse business and industry performance. It is important that any analysis be based upon the range of data presented rather than focusing on one variable.
Where businesses were unable to supply data for the 12 months ended 30 June, an accounting period for which data can be provided is used for data other than those relating to employment.
In the 2011-12 Film, Television and Digital Games Survey, there was an 80.9% live response rate from all businesses that were surveyed and found to be operating during the reference period. Data were imputed for the remaining 19.1% of operating businesses. Imputed responses contributed 6.2% to the estimate of total income.