ATUS-X is a project dedicated to making it easy for researchers to use data from the American Time Use Survey (ATUS). The ATUS is an ongoing time diary study, started in 2003, that is funded by the U.S. Bureau of Labor Statistics and fielded by the U.S. Census Bureau.

Time diary data allow researchers to look at how much time people spend doing different things. The ATUS provides information on time spent in each of more than 400 detailed activities. For certain purposes, it may be of interest to look at activities that people do at particular times of day (for example, paid work that occurs between 11 p.m. and 7 a.m.), in different locations (for example, paid work done at home) or during which the respondent had a child in their care. ATUS-X offers flexible tools for creating time use variables based on the ATUS.

The ATUS-X project assigns uniform codes across all of the data collection years and brings relevant documentation into a coherent form to facilitate analysis of the data. We provide descriptions of all of the variables we offer and, for categorical variables, codes and frequency counts for each year they exist in the data.

The ATUS is composed of microdata. Records may be at the household, person, or activity level. All characteristics on each record are numerically coded. People are organized into households and information on the characteristics of all household members is available, making it possible to analyze people in the context of their families or other co-residents. One person in each household is selected to participate in the American Time Use Survey. These respondents report all of the activities they engaged in over a 24 hour period. Each activity that is reported constitutes a separate record. Because the data consist of records that refer to individuals and the activities they engage in and not tables, researchers must use a statistical package to analyze the data. The data access system allows users to select only the years and variables they require.

ATUS-X is funded through 2011 by a grant from the National Institute of Child Health and Human Development. In the first phase of the project, we have developed a website for that allows data users to aggregate the time spent in combinations of user-defined activities, restricted if desired by time of day, location and/or whether the person had children in their care during the activity, and to select additional variables that characterize the individual ATUS respondents and their household. We will continue to improve our website and documentation. Over the next three years, we plan an annual data system release each June. In the release scheduled for June 2009, we will add the ability to create time use variables that consider the amount of time spent with other household members or with particular groups of non-household members and time engaged in food and eating related secondary activities . Later planned additions include the addition of the capacity to generate customized weights for use in conjunction with user-defined sample populations (2010) and to link ATUS data with CPS Basic Monthly Survey and Supplement data (2011).

We have every expectation of continuing the project beyond 2011 provided the American Time Use Survey continues to be funded, but will have to secure further funding as our current grant expires. To be successful, we need to have a large body of users and published works that we can document. Please inform us of any preparations you may give or papers you may write using ATUS data.

The ATUS data files released by the Bureau of Labor Statistics are complex and considerable programming effort may be required to create even relatively simple time use variables. The ATUS-X data access system makes it easy for users to create the time use variables they want, thus making the data more accessible to a broader audience. The system aggregates time spent in user-specified combinations of activities and applies any requested filters behind the scenes and delivers this information to users in the form of a time use variable.

Further value added derives from the fact that the ATUS-X data are integrated over time, in the sense that uniform codes have been assigned to variables. All codes are fully documented and variable documentation has been compiled in a convenient hyperlinked web format.

The documentation is a natural starting place for new ATUS-X users. First, the User's Guide provides an overview of the database and detailed documentation on the variables and samples available.

The Variables page is the primary tool for exploring the contents of ATUS-X. On the variables page, clicking on a variable name brings up its documentation. The documentation contains a description of the variable as well as the codes, labels, and frequencies for all categorical variables and availability of the variable across samples. This information can suggest the types of research possible with a given sample.

If you are already registered to use ATUS-X, you can click on create an extract and use the data access system.

Access to the ATUS-X documentation is freely available without restriction; however, users must register in order to extract data from the website.

ATUS microdata consist of individual records containing information collected on people, their households, and their activities. The unit of observation is the individual. The responses of each person to the different questions are recorded in separate variables.

Microdata stand in contrast to more familiar "summary" or "aggregate" data. Aggregate data are compiled statistics, such as a table showing the average amount of time each day that parents spend taking care of their children. There are no such tabular or summary statistics in the ATUS data.

Microdata are inherently flexible. You do not need to depend on published statistics that compiled the data in a certain way, if at all. You can generate your own statistics from the data in any manner desired, including individual-level multivariate analyses.

Weights are necessary to produce meaningful summary statistics based on the ATUS data. There are several features of the sampling and data collection process that make weights necessary. First, people and households with some characteristics are over-represented in the data, while others are underrepresented. Second, weekend days are oversampled - half of the respondents report activities that occurred on a weekend day while the other half reported on activities that occurred on a weekday. In addition, response rates differ across demographic groups and days of the week. For these reasons, some ATUS records represent more cases than others and weights allow you to take this into account in analyzing the data.

Most statistical packages have an option that allows you to specify a weight to be used for calculations you carry out. For most person-level analyses of data extracted using ATUS-X, the WT06 variable should be specified. WT06 gives the number of person-days in the month represented by each survey response.

The universe is the population at risk of having a response for the variable in question. In most cases these are the households or persons to whom the question was asked. For example, only people who are employed are asked questions about their earnings on the job. Cases that are outside of the universe for a variable are labeled "NIU" in the codes and frequencies sections of the variable descriptions.

The universes typically take one of four forms:

• All ATUS respondents: Variables with this universe (or some variant) were collected at the time of the ATUS interview and are only available for the one person in each household who responded to the ATUS.


• All ATUS respondents and their household members: Variables with this universe (or some variant) are available for all individuals who were in the household at the time of the ATUS interview; these include RELATE, SEX, and AGE.


• All Current Population Survey (CPS) household members: Variables with this universe (or some variant) are available for all individuals who were in the household at the time of the CPS interview, which occurred 2-5 months prior to the ATUS interview.


• All ATUS (or CPS) households: Variables with this universe (or some variant) are available for all households in the survey indicated.

The universes will not always be entirely clean of apparently erroneous cases. Some people or households that should not have answered the question will have done so, and some that should have answered may be included in the "NIU" (not in universe) category. With the exception of the variables we construct for the convenience of users, these errors reflect problems in the original data.

Potential respondents to the ATUS were drawn from the outgoing rotation group of the Current Population Survey (CPS). The original ATUS public use files contain information on all sampled households and individuals whether or not they participated in the ATUS. To reach the broadest audience possible with our efforts, we have preserved much of the original detail in the public use files including household members of respondents and households in the CPS whose designated respondent did not participate in the ATUS.

We expect that most users will select the "ATUS respondents" samples. Though time use information is only available for designated respondents, users who are interested in the characteristics of other household members may wish to select "ATUS respondents and members of their households," though a number of variables pertaining to the characteristics of other household members are available for selection directly through the ATUS-X data access system

Respondents invited to participate in the ATUS were drawn from outgoing rotation groups of the Current Population Survey (CPS). ATUS interviews occurred 2-5 months after the final CPS interviews. The ATUS public use files allow users to link information about ATUS respondents, non-respondents, and their household members to the most recent CPS data available for all individuals and households invited to participate in the ATUS. Some of the questions asked in the CPS were asked again at the time of the ATUS interview. Examples of questions asked on both occasions include EMPSTAT and EMPSTAT_CPS8; AGE and AGE_CPS8; and EARNWEEK and EARNWEEK_CPS8. In these cases, the _CPS8 extension is used to distinguish the response given at the time of the CPS interview from updated responses collected 2-5 months later during the ATUS interview.

Some information collected at the time of the CPS interview, mostly detailed information about respondents' jobs, was not updated during the ATUS interview. Examples of such information include IND_OJ_CPS8. OCC_OJ_CPS8, and UNION_CPS8. In these cases, the _CPS8 extension tells the data user that the information was collected during the CPS interview rather than the ATUS interview.

The majority of information collected at the time of the ATUS interview is only available for ATUS respondents. Limited information on ATUS respondent household members was collected (see RELATE, SEX, and AGE).

Time use variables are user-defined combinations of activities and/or filters that limit attention to activity based on the time of day it occurred, where it occurred or whether the person had a child in their care during the activity. Time use variables return the number of minutes respondents spend during the 24-hour reference period in activities matching the specified criteria. ATUS respondents reported the activities they engaged in over a 24-hour period from 4 a.m. to 4 a.m. They also reported where and when these activities took place as well as whether they were also caring for a child under 13 during the activity.

You can create your own time use variables in the ATUS data access system by selecting the activities of interest and restricting them to certain locations, times of day, or type of secondary child care. For example, if you were interested in studying shift work, you might create two time use variables by combining Work and Work Related activities with a time filter for two paid work shifts: first shift (7 a.m. to 3 p.m.) and second shift (3 p.m. to 11 p.m.). You could analyze the individual and occupational characteristics of individuals who work during the first shift with those who work during the second shift.

The ATUS diary covers a 24-hour period that begins at 4 a.m. on one day and ends at 4 a.m. the next day. In the current version of the data extract builder, users are not permitted to specify a time interval for the time filter to be applied in creating time use variables that begins before 4 a.m. and ends after 4 a.m. To capture the time spent during such an interval, you must create two time use variables, one for the portion of the interval before 4 a.m. and the second for the portion of the interval after 4 a.m. These two variables then may be summed once you have received your data extract.

Suppose, for example, that you are interested in time spent sleeping during the hours between 11 p.m. and 7 a.m. The data extract builder will not allow you to enter a start time of 11 p.m. and an end time of 7 a.m. for your time filter. Instead, you should create one variable for minutes spent sleeping between 11 p.m. and 4 a.m. and then a second variable for minutes spent sleeping between 4 a.m. and 7 a.m. The sum of these two variables will equal minutes spent sleeping between 11 p.m. and 7 a.m.

Not at this time. Features to support management of user-defined time use variables, including the ability to delete variables, will be developed for future ATUS-X releases.

ATUS-X data are delivered through our data access system. Users select the years they are interested in, create and select time use variables, and select person and household characteristic variables. The system then creates a custom-made extract containing only this information. To start, users can reference our instructions for opening an extract on your computer.

Data are generated on our server. The system sends out an email message to the user when the extract is completed. The user must download the extract and analyze it on their local machine. Access to the documentation is freely available without restriction; however, users must register in order to extract data from the website.

ATUS-X produces fixed-column ASCII data. The data are entirely numeric. The extraction system rectangularizes the data: That is, it puts household information on the person records and aggregates time spent in user-defined activities and puts time use variables on the person records. The rectangularized data file does not retain households or activities as separate records. No information is lost by rectangularizing the data and this is the format preferred by most researchers. In the future, the extraction system will include the option of requesting data in different formats.

In addition to the ASCII data file, the system creates a statistical package syntax file to accompany each extract. The syntax file is designed to read in the ASCII data while applying appropriate variable and value labels. SPSS, SAS, and Stata are supported. You must download the syntax file with the extract or you will be unable to read the data. The syntax file requires minor editing to identify the location of the data file on your local computer.

A codebook file is also created with each extract. It records the characteristics of your extract and should be downloaded for your records.

The time needed to make an extract depends on the number and size of samples requested and the load on our server. Extracts can take from a few minutes to an hour or more. The system sends an email when the extract is completed, so there is no need to stay active on the ATUS-X site while the extract is being made.

The explanation is likely that you cannot open the data file directly with a statistical package. The file is a simple ASCII file, not a system file in the format of any statistical package. The extract system does, however, generate a syntax (set-up) file to read the ASCII file into your statistical package. You must download the syntax file along with the data file from our server, open the syntax file with your statistical package, and edit the path in the syntax file to point to the location of the data on your local computer. Now you are ready to read in the data

ATUS-X supports SPSS, SAS and Stata. The system does not make data files in those formats, but generates syntax files with which to read in the ASCII data.

At this time, users are not able to analyze ATUS-X data online.

All original ATUS data are available from the Bureau of Labor Statistics.

The ATUS data contain information for only one member of each household over one 24-hour period.

With the exception of secondary child care -- defined as having a child in one's care while engaged in another activity -- information on secondary activities is not routinely collected. Additional questions administered as part of the Eating and Health module beginning in January 2006 and scheduled to continue through December 2008 have collected information on eating as a secondary activity, but this is not done as part of the basic survey questionnaire.

Although the ATUS sample size is large relative to past time use studies, the ATUS is a sample survey and there may be too few observations for those in some subpopulations to study them separately.

Because the data are public-use, measures have been taken to assure confidentiality. Names and other identifying information are suppressed, and the geographic information recorded in the ATUS data files is limited.

Reports and publications using ATUS-X data must be cited appropriately. The citation is:

Katharine G. Abraham, Sarah M. Flood, Matthew Sobek, and Betsy Thorn. 2008. American Time Use Survey Data Extract System: Version 1.0 [Machine-readable database]. Maryland Population Research Center, University of Maryland, College Park, Maryland, and Minnesota Population Center, University of Minnesota, Minneapolis, Minnesota.

If possible, citations should also include the URL for the ATUS-X site: http://www.atusdata.org.

We ask that you notify us by email of any publications, research reports, presentations, or educational material making use of the data or documentation. Continued funding for the ATUS-X depends on our ability to show our sponsor agencies that the data are being used for productive purposes.