# How Australians Use Their Time methodology

Latest release
Reference period
2020-21 financial year
Released
7/10/2022
Next release Unknown

### Overview

The 2020-21 Time Use Survey (TUS) was conducted from November 2020 to July 2021. The survey provides data at a national level.  Data was collected from approximately 2000 households around Australia.

The survey was designed to provide insight into how Australians spend their time in a day, including:

• the types of activities undertaken
• the proportion of people who participated in activities
• the average time spent on activities
• differences in how males and females spent their time
• time spent in various locations
• feelings of time pressure

Information about how a person spent their day was collected using a diary. The survey also collected a standard set of information about respondents including age, sex, country of birth, employment, education, and income.

This survey has undergone multiple changes to data collection, processing of data, and classification of activities. Data should be used for point-in-time analysis only and should not be compared to previous years. Refer to the section ‘Comparing the data’ for further information.

### COVID-19 context

The survey was collected during the COVID-19 pandemic. During this time, initiatives were in place to help reduce the spread of COVID-19 including border control measures for some states and territories, stay at home orders, remote learning, shutting down non-essential services, limits on gatherings and social distancing rules.

## Data collection

### Scope

The scope of the survey included:

• all usual residents in Australia aged 15 years and over living in private dwellings, including long-stay caravan parks, manufactured home estates and marinas
• both urban and remote areas in all states and territories, except for very remote parts of Australia and discrete Aboriginal and Torres Strait Islander communities
• members of the Australian permanent defence forces living in private dwellings
• any overseas visitors who have been working or studying in Australian for the last 12 months or more or intend to do so.

The following people were excluded:

• visitors to private dwellings
• overseas visitors who have not been working or studying in Australia for 12 months or more, or do not intend to do so
• members of non-Australian defence forces stationed in Australia and their dependents
• non-Australian diplomats, diplomatic staff, and members of their households
• people who usually live in non-private dwellings, such as hotels, motels, hostels, hospitals, nursing homes and short-stay caravan park
• people in very remote areas
• discrete Aboriginal and Torres Strait Islander communities
• households where all usual residents are less than 15 years of age.

### Sample design

Households were randomly selected to participate in the survey. The sample was designed to support national level estimates and does not support estimates at the state or territory level.

Each household was allocated two consecutive diary dates. The days were selected to be broadly representative of seasonal change across the year (for example, seasonal work and recreation patterns, public holidays, school holidays).

Survey enumeration was conducted in 2020-2021 in the following time periods:

• 11th November – 12th December 2020
• 24th March – 1st May 2021
• 26th May – 3rd July 2021

### Response rates

Information was collected from 2,009 fully responding households, a response rate of 49.3%. From these households, information was collected from 3,630 persons, a response rate of 69.2%. These persons provided a total of 7,062 diary days, a response rate of 67.3%.

Only fully complete records were retained in the final data file. A record was fully complete where there was one diary day with at least 12 hours of activity data reported and at least 3 activities reported.

### Collection method

The TUS survey was collected in two phases. The first phase was a household questionnaire, which was completed by any person in the household aged 15 years or over. They were asked to respond on behalf of all people in the household in scope of the survey. The questionnaire collected demographic and socio-economic information about each person in scope. Households were able to complete the survey online, with an interviewer face-to-face, or over the telephone.

The second phase of collection was a diary, which was designed to collect information about a respondent’s activities over a two-day period. Respondents provided information about their main activity, who they did it for, where they were, and what else they were doing at the same time. The diary also included some questions about health, smoking status, participation in unpaid voluntary work and how respondents felt about their time use. All persons in scope aged 15 years and over were asked to complete the diary through a paper form or online.

## Processing the data

### Processing and coding of diary data

Responses from paper diaries were manually entered into a data entry system.  Changes were only made to correct obvious errors or to amend information to assist coding. Where required, similar amendments were applied to data from the online diaries to align with paper diary data.

If sleep was not recorded in diaries, it was imputed in certain scenarios. This was done at the point of data entry for the paper diaries if it was obvious that sleep had occurred.  It was imputed manually for some online diaries if certain conditions were met.

An automated coding system was used to code activity responses to the Activity Classification.  Logic edits were then applied to activity codes using additional information from the diary data or from the household questionnaire. Quality assurance was done on coding outputs.

The following items were collected in the diaries and have not been published due to data quality concerns:

• Whether a smartphone, table or computer was used to do the activity
• Who was present during the activity

### Estimation methods

As only a sample of people were surveyed on certain days, results needed to be converted into estimates for the whole population. This was done through a process called weighting.

• Each person or household was given a number (known as a weight) to reflect how many people or households they represent in the whole population.
• A person or household’s initial weight was based on their probability of being selected in the sample. For example, if the probability of being selected in the survey was one in 45, then the person would have an initial weight of 45 (that is, they would represent 45 people).

The person and household weights were then calibrated to align with independent estimates of the in-scope population, referred to as ‘benchmarks’. The benchmarks used additional information about the population to ensure that:

• people or households in the sample represent people or households that were similar to them
• the survey estimates reflected the distribution of the whole population, not the sample.

Estimates from the survey were obtained by weighting the diary day responses to represent the in-scope population of the survey.

• a day’s initial weight was based on the probability of the person being selected and assigned a specific type of day (weekday or weekend day).
• the day weights were then calibrated to the person benchmarks to ensure the sample of days represents the people who were similar to them.
• the day estimates reflect the distribution of the whole population of people.

Benchmarks align to the estimate resident population (ERP) aged 15 years and over at April 2021 (after exclusion of people living in non-private dwellings, very remote areas of Australia, and discrete Aboriginal and Torres Strait Islander communities).

TUS weights were also calibrated to labour force status and education attainment, to better compensate for undercoverage in data collection arising from collecting during the COVID pandemic.

## Key concepts

### Activities

Activities are the tasks that are done during a person’s day (for example, eating, sleeping and working).  Participants were asked to report the main activity they were doing, referred to as the primary activity and, what they were doing at the same time, referred to as the secondary activity. The activity information was then coded to the Activity Classification.

### Four types of time

The way people use time is divided into four broad categories:

• Necessary time - includes activities which serve basic physiological needs such as sleeping, eating, personal care, health, and hygiene.
• Contracted time - includes activities where a respondent has a contracted obligation to partake in the activity, such as paid employment and formal education. Also includes related activities such as job search, homework, and related travel.
• Committed time – includes activities which are unpaid work in nature.  This includes domestic activities such as cooking, housework, shopping, gardening, pet care and managing the household.  It also includes child care activities, caring for adults and voluntary work.
• Free time – includes activities generally performed for enjoyment or personal fulfilment. Includes watching television, sport and exercise, social interaction, reading, and other social, recreation and leisure activities.

### Activity Classification

Activities reported by respondents were coded to the Activity Classification.

### No activity

No activity Includes:Time when information was missing from the diary, or the diary day was incomplete.When there was no other applicable code available to describe the activity.

### Personal care activities

Sleeping Includes:Sleeping, napping, dozing during either night or daytime for any length of time.Time in bed before and after sleep, e.g., when respondent stated, ‘went to bed' or 'woke up'.Excludes:Resting or relaxing is coded to 'Relaxing’. Includes:Trying to sleep, unable to sleep, woken by disturbance. Includes:Toilet, showering, dressing, brushing teeth and other bathroom activities.Using personal care services such as hairdresser.Getting self ready, e.g., getting ready for bed, work, sport, and leisure. Includes:Health or medical appointments.Taking medications and health measurements.Exercises for medical conditions.Resting or in bed due to pain or illness.Excludes:Exercise for general fitness is coded to 'Exercise, sport and outdoor activity'.Massages and meditation are coded to 'Other personal care'. Includes:Meals, snacks, drinks, tea or coffee, alcoholic drinks.Lunch breaks, morning or afternoon tea or coffee or tea break whilst at work or study.Excludes:Eating and drinking at a dining venue is coded to 'Eating and drinking out'. Includes:Travel for own health care such as to or from doctors, medical appointments, hospital.Travel to and from personal care services such as hairdressers. Includes:When there was no other applicable code for a personal care activity.Massages, meditation, intimacy.

### Employment related activities

Work Includes:All activities recorded as 'work' or where an activity was done 'for work'.Working from home.Job-related training.Checking work emails outside working hours.Breaks whilst at work (excluding eating or drinking).Excludes:Lunch, coffee, morning tea and afternoon tea are coded to 'Eating and drinking' or ‘Eating and drinking out’. Includes:Job search, job applications, preparing resume, job interviews. Includes:Travel to and from work.Excludes:Travel as part of work, for example, courier, driver, or driving from one worksite to another is coded to 'Work'. Includes:When there was no other applicable code for an employment related activity.Excludes:Getting ready for work is coded to 'Personal hygiene'.

### Education activities

Formal education Includes:Participation in lectures, tutorials, exams, school classes.Participation in school, TAFE, college, university.In person or online education.Recess and other breaks between classes (excluding eating and drinking).Homework, study.Excludes:Lunch breaks are coded to 'Eating and drinking'.Participation in non-formal courses is coded to 'Participation in non-formal course'.Job related training is coded to 'Work'. Includes:Travel to and from own school, university, college.Excludes:Taking a child to or from school or daycare, is coded to 'Travel associated with child care activities'.Taking family or household members aged 15 years or over to educational institutions is coded to 'Travel associated with domestic activities'. Includes:When there was no other applicable code for an activity related to a respondent’s own education.Applying for university course, communication with school, checking timetable.Excludes:Getting ready for school is coded to 'Personal hygiene'.

### Domestic activities

Food and drink preparation/service Includes:Preparing or cooking food and drinks.Excludes:Food preparation or cooking exclusively for children is coded to ‘Feeding and food preparation for children’.Food preparation or cooking for animals is coded to ‘Pet and animal care’.Cleaning up after food preparation is coded to ‘Housework’. Includes:Shopping for food, groceries, or other goods.Any response which states shopping, shops, bought, buying, ordering.Shopping in person or online.Unpacking groceries or shopping.Excludes:Window shopping is coded to ‘Other recreation and leisure’. Includes:Indoor house cleaning or tidying.Dishes and clean up after meals.Clothes washing, laundry and ironing. Includes:Watering plants, garden, lawn.Mowing and lawn care.Cleaning outdoor areas. Includes:Cleaning car and vehicles.Maintenance on cars, bikes, boats.Performing or arranging home renovations and repairs.Excludes:Fixing up old cars or bikes as a hobby is coded to ‘Hobbies and arts’. Includes:Administrative tasks for household such as finance, bills, post.Planning or organising on behalf of household.Disposing of rubbish.Filling in time use diary.Packing or unpacking car. Includes:Feeding animals.Walking and playing with animals. Includes:Travel to and from shopping.Travel associated with domestic activities. Includes:When there was no other applicable code for a domestic related activity.‘Household duties’ and ‘household chores’ without any further information.Helping children aged 15 years or over with homework.Pottering around the house or garage.

### Child care activities

Child care activities can be performed for children who live either in or out of the household and can be for children who are family or not family. It is intended that child care activities are performed for children under the age of 15 years, although this detail is not always clear in the time use diaries.

Physical and emotional care of children Includes:Bathing, dressing, toileting, changing nappies, brushing teeth.Putting children to bed, waking children up, settling babies.Getting children ready, e.g., for bed, school, or outings.Excludes:Food preparation for children is coded to ‘Feeding and food preparation for children’.Feeding babies and preparing bottles for babies’ is coded to ‘Feeding and food preparation for children’. Includes:Helping with homework, schoolwork, helping with other studies, reading.Helping children do things or showing them how, directions about household chores. Includes:Playing with child, reading to child, talking to child.Watching TV or movies with children. Includes:When a response indicates there is supervision of a child but there is no further information about the activity, such as babysitting, minding child, looking after child. Includes:Attending a child’s sport or extra-curricular activities or classes. Includes:Feeding baby, expressing breast milk, preparing bottles.Making meals for child where the response indicates it was exclusively for children.Excludes:Preparing dinner for the whole family or household is coded to ‘Food and drink preparation/service’. Includes:Taking children to or picking them up, e.g., to or from school, daycare, classes.Waiting for children when picking them up. Includes:When there was no other applicable code for a child care related activity.Talking to child care providers.

Physical care for adults (sick, with disability or aged) Includes:Care for people aged 15 years or over who are sick, with disability or aged.Help with personal hygiene, bathing, dressing, toileting and feeding.Providing medical and health care. Includes:Driving to or from hospital, aged care homes, doctor’s or medical appointments for an adult who is sick, with disability, aged. Includes:When there was no other applicable code for an adult care activity.Emotional care or support for people. Checking on their welfare, comforting.Visiting people in hospital or in aged care facility.

### Voluntary work activities

Voluntary work Includes:Responses of ‘volunteering’.Activities done for community or charity which are not paid work, e.g., sports coaching. Includes:Helping a friend or neighbour with tasks such as gardening, transport, home maintenance, cooking.Excludes:Activities done for people who are sick, with disability, aged are coded to the relevant category within 'Adult care activities'. Includes:Travel associated with getting to or from voluntary work or to or from helping a friend or neighbour. Includes:When there was no other applicable code for a voluntary work related activity.

### Social and community interaction

Social interaction Includes:Socialising with friends and family. Having visitors over.General talking.Phone calls, messaging, video calls.Excludes:Attendance at weddings or funerals is coded to 'Religious and cultural practices'.Where it is indicated the person is dining or drinking at a venue, for example, restaurant, café, pub it is coded to 'Eating and drinking out'.Talking exclusively to children is coded to 'Playing/reading/talking with child'.All references to emailing or posting on social media is coded to 'General internet and device use'. Includes:Spectating sports match or event.Watching adult family member aged 15 years or over play sport.At library when no further information is given.Racing events such as going to the horse racing or dog racing.Attending cinema, performing arts, amusement parks, exhibitions, festivals, museum.Excludes:Attending a venue exclusively 'with or for kids' e.g., movies, library, park, is coded to 'Minding child'.Visiting library for education activities is coded to 'Formal education'.Visiting a park where no other activity is indicated is coded to 'Exercise, sport and outdoor activity'.Watching children play sport is coded to 'Accompanying child to school or extra-curricular activities'. Includes:Eating or drinking at a dining venue, for example, restaurant, café, pub.If person was on their own or with others. Includes:Prayer - alone or with others.Attending church, places of worship and religious services.Participating in bible or theme study groups.Reading the bible or other religious texts.Attending weddings, funerals, christenings.Visiting a cemetery.Graduation ceremonies, presentations. Includes:Attendance at council, community, or school meetings.ANZAC day service or marches.Attending police stations.Driving lessons, practice and driving tests.COVID-19 mandates such as check-ins. Includes:Travel associated with social and community interaction.Travel associated with eating and drinking out. Includes:When there was no other applicable code for an activity related to social and community interaction.

### Participants

A person who reported in their time use diary that they spent at least five minutes in their day doing an activity.

### Proportion who participated in activity

This is the proportion of persons in a population who have spent at least five minutes on an activity in a day.  It is calculated:

$$\mathsf{\large{\frac{\text{Persons in population who participated in activity}}{\text{Total persons in population}}\times 100}}$$

For example, the proportion of females who participated in domestic activities:

$$\mathsf{\large{\frac{\text{Females who participated in domestic activities}}{\text{Total females}}\times 100}}$$

Summing the ‘proportions who participated in an activity’ for more than one activity in the datacubes will double count people who appear in more than one category and will not give an accurate total.

### Average time spent per day, of persons who participated in activity

The average time spent on an activity by people who reported spending at least five minutes in the day doing this activity, is calculated by:

$$\mathsf{\large{\frac{\text{Total time spent on activity in a day by persons in the population}}{\text{Persons in population who participated in activity}}}}$$

For example, the average time spent per day of females who participated in domestic activities:

$$\mathsf{\large{\frac{\text{Total time females spent on domestic activities in a day}}{\text{Females who participated in domestic activities}}}}$$

This average is particularly useful for reporting the average time spent on activities that the whole population did not participate in, for example work or child care.  This is because the average time is calculated only including those persons who participated in the activity.  For example, of the persons who participated in work, they spent an average of 7 hours 15 minutes per day.

Summing the ‘average time spent per day, of persons who participated in activity’ for more than one activity in the datacubes will double count people who appear in more than one category and will not give an accurate total.

The average time spent per day of persons who participated in separate activity categories cannot be summed together to calculate a total average.

### Average time spent per day, of total population

The average time spent on an activity by all people, regardless of whether they reported doing that activity in their day or not, is calculated by:

$$\mathsf{\large{\frac{\text{Total time spent on activity in a day by persons in the population}}{\text{Persons in population}}}}$$

For example, the average time spent per day on domestic activities by all females:

$$\mathsf{\large{\frac{\text{Total time females spent on domestic activities in a day}}{\text{Total females}}}}$$

The average time spent per day of the total population can result in very small amounts of average time per day if the proportion of the population that participated in the activity is low.  For these scenarios, this average time statistic may not be very useful. For example, the average time spent per day on child care of the total population will include people who do not spend any time caring for children.

The average time spent per day of the total population from separate activity categories can be summed together to calculate a total average.

## Data quality

### Inconsistency between household questionnaire and diary

In a small number of instances there are inconsistencies between the data provided in the household questionnaire and the diary. For example, a person may be reported as unemployed in the household questionnaire but has reported spending time on employment in their diary.

These differences could be due to:

• a change of circumstance; the diary is collected 1 to 2 weeks after the household questionnaire
• the person completing the household questionnaire may not have correct information about the person they are responding for
• a person may not have participated in an activity on the day they were asked to complete the diary.  For example, an employed person may have completed their diary on a non-work day.

### Prevalence of participation

The 2020-21 TUS is not designed to provide counts of people by prevalence (such as employment, voluntary work, disability status or caring status), rather to identify population groups, so that analysis can be undertaken on how they reported spending their time.

The proportion who participated does not reflect the prevalence rate of a characteristic in the general population. For example, the proportion who participated in adult care activities is not the equivalent of the proportion of carers in the population. This is because each participant completes only two diary days and a carer may not have provided any care on their diary day.

### Under coverage of activities

There may be under coverage of time spent on activities because a person could be doing more than two of the possible activities at the same time, however the diary only allows for collection of two activities at a given time.

### Primary and Secondary activities

Respondents could report two activities at the same time, a primary activity, and a secondary activity (what they were doing at the same time).  For example, cooking dinner and listening to the radio.

In a small number of instances, the primary and secondary activities could have been coded to the same activity category. For example, cooking dinner and setting the table are both coded to Food and drink preparation/service. Reporting on the time spent for primary and secondary activities combined may inflate the time spent on that activity category.

Due to data quality concerns, the secondary activity was not output by itself.

### Classifying activities

One fundamental difficulty with classifying activities is that one activity could be coded to multiple activity categories.  In the 2020-21 TUS, activities were coded to the category that was deemed the most relevant.

For example;

• a response of lunch with friends was coded to the social and community interaction category of eating and drinking out rather than to the personal care activity of eating and drinking.
• a response of made lunch for kids was coded to the child care activity of feeding and food preparation for children rather than the domestic activity of food and drink preparation/service.

## Comparing the data

The 2020-21 TUS data is a source of point-in-time data and should not be compared to previous years. See below for further information about changes to the survey.

If you choose to make comparisons between 2020-21 TUS and previous surveys, the ABS recommends caveating the data with the following statement: The 2020-21 Time use estimates are not fully comparable with previous collections due to changes in methodology.

### Changes to the data collection

There have been multiple changes to the data collection of the survey which may impact on the types of responses provided by participants. These include:

• COVID-19 impacts on how people spent their time and on survey enumeration
• the introduction of online collection, both for the household questionnaire and the diary
• lower response rate than the previous survey
• changes to the content of the household questionnaire and diary

### Changes to processing and coding of diary data

There have been multiple changes to the processing of 2020-21 TUS survey data which impact comparability with previous releases.  These include:

• introduction of an automated coding process
• reduced manual intervention of data (micro-editing and imputation)

### Changes to the Activity Classification

The 2020-21 TUS activity classification was reviewed and updated to align with real-world changes in how people spend their time and the level of detail provided by respondents in their diaries. The classification is not directly comparable to the activity classification used in the previous release of the survey. See the table below for details of the changes.

### Summary of changes

2020-21 TUS Activity Classification Changes
Changes
OVERALL
• Reduction in the level of detail
• Categories removed and spread throughout the 2020-21 TUS classification (e.g. Purchasing goods and services)
• Activities have been coded to different activities
PERSONAL CARE ACTIVITIES

Includes:

• Purchasing personal care or medical services (e.g. doctor’s appointments, hairdressers)
• Dozing/staying in bed

Excludes:

• Eating and drinking out
Sleeping

Includes:

• Dozing/staying in bed
Personal hygiene

Includes:

• Purchasing personal care services (e.g. hairdressers)
Personal health care

Includes:

• Purchasing medical services (e.g. doctor’s appointments)
Eating and drinking

Excludes:

• Eating and drinking out
EMPLOYMENT RELATED ACTIVITIES

Includes:

• Job related training

Excludes:

Work

Includes:

• Main job
• Other job
• Unpaid work in family business
• Work breaks
• Job related training
Other employment related activities

Excludes:

EDUCATION ACTIVITIES

Excludes:

• Job related training
Formal education

Includes:

• Attendance at educational courses
• Homework/study/research
• Breaks at place of education

Excludes

• Job related training
Other education activities

Excludes:

DOMESTIC ACTIVITIES

Includes:

• Purchasing goods and associated travel
• Filling in time use diary
• Interacting with pets
• Activities done for family both in and out of household

Excludes:

• Food preparation for children
Food and drink preparation/service

Excludes:

• Food preparation for children
• Clean up after food preparation
Shopping

Includes:

• Packing away shopping
Housework

Includes:

• Laundry and clothes care
• Clean up after food preparation
• Occasional housework
• All other housework
Grounds care and gardening

Excludes:

• Pet, animal care
• Walking pets
Pet and animal care

Includes:

• Walking pets
• Interacting with pets
Household management

Includes:

• Filling in time use diary

Excludes:

• Packing away shopping
CHILD CARE ACTIVITIES

Includes:

• Food preparation for children
• All child care whether child lives in or out of household
Physical and emotional care of children

Includes:

• Emotional care of children

Excludes:

• Infant feeding
Feeding and food preparation for children

This is a new category

Includes:

• Food preparation done exclusively for children
• Infant feeding

This is now a separate category from 'Voluntary work'

• In TUS 2020-21, adult care activities may not have been captured in all cases because the diary does not ask whether the activity was done for someone who was sick, with disability or aged. Other contextual information in the diary (i.e. prior or later episodes which indicated care) may not have been considered
• In TUS 2006, a physical activity was coded to adult care if:
• The recipient of the activity was likely to be aged 60 years or over
• The household questionnaire indicated that the recipient had a long-term health condition
• The activity was coded as being done for someone 'sick/aged/disabled'
• It was a physical activity done for adults such as 'cutting partner's hair'

Excludes:

Includes:

VOLUNTARY WORK ACTIVITIES

This is now a separate category from 'Adult care activities'

Excludes:

• Activities done for family both in and out of the household
Help/favour for friend/neighbour

Excludes:

• Activities done for family both in and out of the household
SOCIAL AND COMMUNITY INTERACTION

Includes:

• Talking/chatting
• Eating and drinking out

Excludes:

• Filling in time use diary
Social interaction

Includes:

• Associated communication to recreation and leisure
Visiting entertainment and cultural venues

Includes:

• Attendance at sports events
Community participation

Excludes:

• Filling in time use diary
RECREATION AND LEISURE ACTIVITIES

Excludes:

• Talking/chatting
• Interacting with pets
• Dozing/staying in bed
Games

Excludes:

• Hobbies/arts/crafts
Watching TV and video

Includes:

• TV watching/listening
• Video/DVD watching

Includes:

• Listening to records/tapes/CDs and other audio media
General internet and device use

This is a new category

Includes:

• Using the internet, general computing
Hobbies and arts

Excludes:

• Games
Other recreation and leisure activities

Excludes:

• Dozing/staying in bed

### Changes to the data release

Due to data quality concerns, several data items released in the 2006 publication were considered unsuitable for publication in 2020-21 TUS. These included:

• Who the activity was done for
• Who was present during the activity
• Spatial location
• Mode of transport
• Type of communication/technology used
• Nature of activity

### Comparability with other ABS surveys and non-ABS sources

Estimates from 2020-21 TUS may differ from the estimates for the same or similar data items produced from other ABS collections for several reasons. Differences in sampling errors, scope, collection methodologies, reference periods, seasonal and non-seasonal events may all impact estimates.

## Accuracy

### Show all

#### Reliability of estimates

Two types of error are possible in estimates based on a sample survey:

• non-sampling error
• sampling error.

#### Non-sampling error

Non-sampling error is caused by factors other than those related to sample selection.  It is any factor that results in the data values not accurately reflecting the true value of the population.

It can occur at any stage throughout the survey process. Examples include:

• selected people that do not respond (e.g. refusals, non-contact)
• questions being misunderstood
• responses being incorrectly recorded
• errors in coding or processing the survey data.

#### Sampling error

Sampling error is the expected difference that can occur between the published estimates and the value that would have been produced if the whole population had been surveyed. Sampling error is the result of random variation and can be estimated using measures of variance in the data.

#### Standard error

One measure of sampling error is the standard error (SE). There are about two chances in three that an estimate will differ by less than one SE from the figure that would have been obtained if the whole population had been included. There are about 19 chances in 20 that an estimate will differ by less than two SEs.

#### Relative standard error

The relative standard error (RSE) is a useful measure of sampling error. It is the SE expressed as a percentage of the estimate:

$$\mathsf{RSE\%=\frac{SE}{estimate}\times100}$$

Only estimates with RSEs less than 25% are considered reliable for most purposes. Estimates with larger RSEs, between 25% and less than 50%, have been included in the publication, but are flagged to indicate they are subject to high SEs. These should be used with caution. Estimates with RSEs of 50% or more have also been flagged and are considered unreliable for most purposes. RSEs for these estimates are not published.

#### Margin of error for proportions

Another measure of sampling error is the margin of error (MOE). This describes the distance from the population value that the sample estimate is likely to be within and is particularly useful to understand the accuracy of proportion estimates. It is specified at a given level of confidence. Confidence levels typically used are 90%, 95% and 99%.

For example, at the 95% confidence level, the MOE indicates that there are about 19 chances in 20 that the estimate will differ by less than the specified MOE from the population value (the figure obtained if the whole population had been enumerated). The 95% MOE is calculated as 1.96 multiplied by the SE:

$$\mathsf{MOE=SE\times1.96}$$

The RSE can also be used to directly calculate a 95% MOE by:

$$\mathsf{MOE(y)\approx \frac{RSE(y)\times y}{100}\times 1.96}$$

The MOEs in this publication are calculated at the 95% confidence level. This can easily be converted to a 90% confidence level by multiplying the MOE by:

$$\mathsf{\large{\frac{1.615}{1.96}}}$$

or to a 99% confidence level by multiplying the MOE by:

$$\mathsf{\large{\frac{2.576}{1.96}}}$$

Depending on how the estimate is to be used, an MOE of greater than 10% may be considered too large to inform decisions. For example, a proportion of 15% with an MOE of plus or minus 11% would mean the estimate could be anything from 4% to 26%. It is important to consider this range when using the estimates to make assertions about the population.

#### Confidence intervals

A confidence interval expresses the sampling error as a range in which the population value is expected to lie at a given level of confidence. A confidence interval is calculated by taking the estimate plus or minus the MOE of that estimate. In other terms, the 95% confidence interval is the estimate +/- MOE.

#### Calculating measures of error

Proportions or percentages formed from the ratio of two estimates are also subject to sampling errors. The size of the error depends on the accuracy of both the numerator and the denominator. A formula to approximate the RSE of a proportion is given below. This formula is only valid when the numerator $$\mathsf{\small{(x)}}$$ is a subset of the denominator $$\mathsf{\small{(y)}}$$:

$$\mathsf{RSE (\frac {x}{y}) = \sqrt {[RSE(x)]^2 - [RSE(y)]^2}}$$

When calculating measures of error, it may be useful to convert RSE or MOE to SE. This allows the use of standard formulas involving the SE. The SE can be obtained from RSE or MOE using the following formulas:

$$\mathsf{\large{SE = \frac{RSE\% \times estimate}{100}}}$$

$$\mathsf{\large{SE = \frac{MOE}{1.96}}}$$

#### Comparison of estimates

The difference between two survey estimates (counts or percentages) can also be calculated from published estimates. Such an estimate is also subject to sampling error. The sampling error of the difference between two estimates depends on their SEs and the relationship (correlation) between them. An approximate SE of the difference between two estimates $$\mathsf{\small{(x-y)}}$$ may be calculated by the following formula:

$$\mathsf{SE(x-y) \approx \sqrt {[SE(x)]^2 + [SE(y)]^2}}$$

While this formula will only be exact for differences between unrelated characteristics or sub-populations, it provides a reasonable approximation for the differences likely to be of interest in this publication.

#### Significance testing

When comparing estimates between surveys or between populations within a survey, it is useful to determine whether apparent differences are 'real' differences or simply the product of differences between the survey samples.

One way to examine this is to determine whether the difference between the estimates is statistically significant. This is done by calculating the standard error of the difference between two estimates $$\mathsf{\small{(x \text{ and } y)}}$$ and using that to calculate the test statistic using the formula below:

$$\mathsf{\Large{\frac{[x-y]}{SE(x-y)}}}$$

where

$$\mathsf{{SE(y) \approx \frac{RSE(y) \times y}{100}}}$$

If the value of the statistic is greater than 1.96, we can say there is good evidence of a statistically significant difference at 95% confidence levels between the two populations with respect to that characteristic. Otherwise, it cannot be stated with confidence that there is a real difference between the populations.

## Data release

### Release strategy

The 2020-21 TUS release presents national estimates. The sample design is not sufficient to enable detailed analysis of state and territory estimates.

Data cubes in this release present tables of Estimates, Proportions, and their associated Measures of Error. A data item list is also available in the Data downloads section.

### Microdata

The ABS is currently assessing the feasibility of a microdata product and will update this page once a decision is made.

### Custom tables

Customised statistical tables to meet individual requirements can be produced on request. These are subject to confidentiality and sampling variability constraints which may limit what can be provided. Enquiries on the information available and the cost of these services should be made to the ABS website Contact us page.

### Confidentiality

The Census and Statistics Act 1905 authorises the ABS to collect statistical information and requires that information is not published in a way that could identify a particular person or organisation. The ABS must make sure that information about individual respondents cannot be derived from published data.

To minimise the risk of identifying individuals in aggregate statistics, a technique called perturbation is used to randomly adjust cell values. Perturbation involves small random adjustment of the statistics which have a negligible impact on the underlying pattern. This is considered the most satisfactory technique for avoiding the release of identifiable data while maximising the range of information that can be released. After perturbation, a given published cell value will be consistent across all tables. However, adding up cell values in Data Cubes to derive a total may give a slightly different result to the published totals.

## Glossary

### Show all

#### Carer

A carer is a person who provides any informal assistance (help or supervision) to people with disability or older people. The assistance must be ongoing, or likely to be ongoing, for at least six months.

Carers do not have to live in the same household as the person they care for. Assistance to a person living in a different household to the carer relates to everyday activities, without specific information on the type of activity.

Carers were identified based on their responses to the questionnaire component of the survey.

#### Child

Any individual under 15 years old, usually a resident in the household, who forms a parent-child relationship with another member in the household.

#### Couple

A couple refers to two usual residents, both aged at least 15 years, who are either married to each other or living in a de facto relationship with each other.

#### Disability

A disability or long-term health condition exists if a limitation, restriction, impairment, disease or disorder, has lasted, or was likely to last, for at least six months and which restricted everyday activities.

It is classified by whether or not a person has a specific limitation or restriction. Specific limitation or restriction is further classified by whether the limitation or restriction is a limitation in core activities or a schooling/employment restriction only.

There are four levels of core activity limitation (profound, severe, moderate, and mild) which are based on whether a person needs help, has difficulty, or uses aids or equipment with any of the core activities (self care, mobility or communication). A person's overall level of core activity limitation is determined by their highest level of limitation in these activities.

The four levels are:

• profound - always needs help/supervision with core activities
• severe - does not always need help with core activities
• moderate - has difficulty with core activities
• mild - uses aids to assist with core activities.

Persons are classified as having only a schooling/employment restriction if they have no core activity limitation and are aged 15 to 20 years and have difficulties with education, or are aged 15 years and over and have difficulties with employment.

#### Episode

An episode is defined by the primary activity, secondary activity and location of the activity, at any particular time. A change in any of these elements identifies a new episode.

#### Equivalised weekly household income

Equivalised total household income is household income adjusted by the application of an equivalence scale to facilitate comparison of income levels between households of differing size and composition. This variable reflects that a larger household would normally need more income than a smaller household to achieve the same standard of living. The 'modified OECD' equivalence scale is used.

Equivalised total household income can be viewed as an indicator of the economic resources available to a standardised household. For a lone person household, it is equal to household income. For a household comprising more than one person, it is an indicator of the household income that would be needed by a lone person household to enjoy the same level of economic wellbeing.

#### Family

Two or more persons, one of whom is at least 15 years of age, who are related by blood, marriage (registered or de facto), adoption, step or fostering; and who are usually resident in the same household. The basis of a family is formed by identifying the presence of a couple relationship, lone parent-child relationship or other blood relationship. Some households will, therefore, contain more than one family.

#### Household

One or more persons, at least one of whom is at least 15 years of age, usually resident in the same private dwelling.

#### Income

• wages and salaries (including from own incorporated business)
•  government pension, benefit or allowance
• superannuation, annuities or private pensions
• rental investments
• other regular sources of income

#### Index of Relative Socio-economic Disadvantage

An index within the Socio-Economic Indexes for Areas (SEIFA). The index of relative socio-economic disadvantage includes attributes such as low income, low educational attainment, high unemployment and dwellings without motor vehicles.

The index refers to the attributes of the area (Statistical Area Level 1 at national level) in which a person lives, not the socio-economic situation of a particular individual. For further information about the SEIFAs, see Socio-Economic Indexes for Areas (SEIFA) 2016.

#### Labour force status

Classifies all people aged 15 years and over into one of the following categories:

• employed - during the week before the interview, persons worked one hour or more in a job or business, or undertook work without pay in a family business, or they had a job in the reference week, but were not at work.
• employed full-time - persons who usually worked 35 hours or more per week
• employed part-time - persons who usually worked less than 35 hours per week
• unemployed - not employed and actively looked for work in the four weeks prior to the questionnaire and available to start work in the week prior to the survey
• not in the labour force - people who were not in the categories employed or unemployed

#### Living situation

The following living situations are reported on in the data:

• Parent in couple family with child less than 15 years old - two persons in a registered or de facto marriage who usually live in the same household with at least one child who is less than 15 years old. The family may also include non-dependent children, other relatives and unrelated individuals.
• Other parents in couple family - two persons in a registered or de facto marriage who usually live in the same household with their non-dependent children. The family may also include other relatives and unrelated individuals.
• Lone parent with child less than 15 years old - a family comprising of one parent with at least one child who is less than 15 years old. The family may also include non-dependent children, other relatives and unrelated individuals.
• Other lone parent - a family comprising of one parent who usually lives in the same household with their non-dependent children. The family may also include other relatives and unrelated individuals.
• Partner in couple family with no children - two persons in a registered or de facto marriage who usually live in the same household, but do not live with their own children. This family may also include other relatives and unrelated individuals.
• Non-dependent child – All persons aged 15 years or over (except those aged 15-24 years who are full-time students) who have a parent in the household and do not have a partner or child of their own in the household.
• Dependent child - All persons aged under 15 years; and people aged 15-24 years who are full-time students, have a parent in the household and do not have a partner or child of their own in the household.
• Lone person aged 15 to 64 years old
• Lone person aged 65 years and over
• Other

#### Quintiles

Groupings that result from ranking all households or persons in the population in ascending order according to some characteristic such as their household income and then dividing the population into five equal groups, each comprising 20% of the estimated population.

#### Remoteness

The Australian Statistical Geography Standard (ASGS) was used to define remoteness. The Remoteness Structure is described in detail in the publication Australian Statistical Geography Standard (ASGS): Volume 5 - Remoteness Structure, July 2016.

#### Self-assessed health status

The respondent's general assessment of their own health, against a five point scale from excellent through to poor.

#### Unpaid work

For the purposes of this publication, unpaid work includes domestic, child care, adult care and voluntary work activities.  It is also referred to as Committed Time in this publication.

#### Unpaid voluntary work

The provision of unpaid help willingly given in the form of time, service or skills to a club, organisation or association.

#### Volunteer

Persons who identified that they had done unpaid voluntary work in the previous 12 months for any of the following types of organisations:

• Organised sporting groups and teams
• Youth groups
• A charity organisation or cause
• Student government
• Religious organisation
• School or preschool
• Some other kind of volunteer work

These organisations do not include:

• Internships
• Work experience or work for study purposes
• Unpaid work undertaken overseas
• Unpaid work undertaken to receive a government allowance
• Unpaid work as part of a court order

#### Weekday

Refers to any day during the week from Monday to Friday.

#### Weekend

Refers to any day on the weekend, Saturday and Sunday.

#### Weekly personal income

Regular money received by an individual from all income sources over the course of a week.