When enumeration commenced some dwellings selected for inclusion in the sample were found to have no possibility of delivering a survey response. Collectively these are referred to as sample loss, and are composed of the following groups:
- dwellings which are out of scope of the survey;
- dwellings which are under construction, demolished, or converted to non-private dwellings or non dwellings;
- private dwellings which are vacant;
- private dwellings that contain out of scope residents (e.g. dwellings occupied by foreign diplomats and their dependants); or
- private dwellings that contain only visitors.
The total sample loss was 886 dwellings, 13.4% of the initially selected sample.
Households selected for inclusion in the survey can be categorised as responding or non-responding households. Responding households are either fully responding or partially responding. In the Time Use Survey, some information missing from partially responding households was imputed, as described below in 'Data processing'.
Non-responding households include:
- households affected by death or illness of a household member;
- households in which the significant person(s) in the household did not respond because they could not be contacted, had language problems or refused to participate; and
- households in which the significant person(s) did not respond to key questions.
The following table shows the response rates:
3.1 RESPONSE RATES, households
Number of households
|Fully responding |
|Partly responding |
|Not responding |
|Sample loss |
From the fully and partly responding households, 8,442 persons aged 15 and over were in on scope and coverage for the survey. Fully completed or partially completed questionnaires (including both interview information and diaries), were obtained for 7,672 persons, 90.9% of all persons in on scope.
Number of records on the final file
To maximise the amount of activity data captured, incomplete records with one complete day have been included in the final file. Diary days were considered complete if there were activities recorded for at least 14 hours of the day. Persons with less than 14 hours of useable information for both diary days were dropped from the file. A small number of persons were also deleted from the file when complete household details were not available. Overall 711 persons were dropped from the file because they had no useable diary information or no useable interview details. However, the details of all persons with complete interview information were included in the household and family level derivations as these were derived prior to the deletion of these persons so that correct family and household information would be included on the file.
The number of respondents that were kept on the final file was 6,961 persons (82.5% of all persons surveyed), 3,816 families and 3,643 households contributing 13,732 diary days. Of these, 50.5%(6,941) were for the first specified day and 49.5%(6,791) were for the second specified day. 2.7% of respondents provided only a single diary day.
The quality of data from the second diary day declined very little, as shown by one of the standard measures of data quality in time use surveys, the number of episodes per day. Day one averaged 28.9 and day two 27.0 episodes per day.
These results confirm the usefulness of the two-day diary methodology, providing nearly twice as much data as a single day diary for little extra collection cost.
The distribution of the days of the week and weekday/weekend days on the file is as follows:
Distribution of days