Longitudinal and International Study of Adults (LISA)

Detailed information for 2012 (Wave 1)

The Longitudinal and International Study of Adults collects information from people across Canada about their jobs, education, health and family. The study is interested in how changes in these areas affect people's lives. This study aims to help improve education, employment, training and social services in Canada.

Data release - January 30, 2014

• Questionnaire(s) and reporting guide(s)
• Description
• Data sources and methodology
• Data accuracy

Description

The Longitudinal and International Study of Adults (LISA) is a study that examines changes in Canadian society over time. LISA uses household interviews to collect information from approximately 34,000 Canadians age 15+ years from more than 11,000 households. LISA aims to improve our understanding of what is happening in the lives of Canadians so we can see what services they require, and what kinds of information they need to support their decision-making about today and the future. LISA results could shed light on:

- Long-term impacts of postsecondary education;
- Transitions in the workplace and across the labour force;
- Impacts of complex issues such as job loss and poor health;
- Standards of living for retirees and changes that may occur over time.

Data users include all levels of government, researchers, educators, learning institutions and organizations. These data are used to influence the development of services, and to ensure the development of effective policies and service provision to the people who require it the most.

Reference period: Two years prior to interview date

Collection period: January through May

Subjects

• Education, training and learning
• Families, households and housing
• Health
• Income, pensions, spending and wealth
• Labour

Data sources and methodology

Target population

The Longitudinal and International Study of Adults (LISA) covers the population living in Canada's ten provinces as of the first Wave of the survey (2011), plus their future children. Excluded from the survey's coverage are those living in Canada's territories, as well as those who at the time of Wave 1 were: living on reserves and other Aboriginal settlements in the provinces; official representatives of foreign countries living in Canada and their families; members of religious and other communal colonies; members of the Canadian Armed Forces stationed outside of Canada; living full-time in institutions, for example, inmates of correctional facilities and chronic care patients living in hospitals and nursing homes; or living in other collective dwellings. Altogether these exclusions represent approximately 2% of the population.

Instrument design

The survey is conducted by a Statistics Canada interviewer via a Computer Assisted Personal Interview. The infrastructure was tested in 2011 by Income Statistics Division, Special Surveys Division, Collection Planning and Management Division, Collection Systems and Infrastructure Division.

Survey content was taken from the International Study of Adults (2012). Content was tested in 2010.

Sampling

This is a sample survey with a longitudinal design.

SURVEY FRAME
The LISA sample has a stratified multi-stage, multi-phase design. The LISA survey frame was constructed from dwellings containing households that responded to the 2011 Census of Population and that were not eligible for the National Household Survey (NHS), which was being run at the same time as LISA. It was necessary to restrict the frame to Census respondent dwellings because the household composition was required by the sampling plan. A total of eight 2011 Census Response Database (RDB) tables were extracted to create the frame. The first step was to create the NHS flag to identify all Census responding dwellings selected for the NHS. Some exclusions were then made, including inactive dwellings, dwellings with an invalid questionnaire, and non-respondent dwellings. Exclusions from the target population were then made. Finally, dwellings with only temporary or foreign residents remaining were excluded from the frame. Next, checks were done to ensure that there were no dwelling duplicates or person duplicates on the file.

In Wave 1, LISA was integrated with the Programme for the International Assessment of Adult Competencies (PIAAC), also known as the International Study of Adults (ISA). The two surveys shared a portion of their samples and the data collection activities were integrated, which impacted the LISA sample design. The target populations of the two surveys differed, in that the ISA target population covered only 16 to 65 year-olds, whereas the LISA target population covered individuals of all ages.

Consequently, the frame was first stratified by eligibility status for ISA. It was then further stratified by province and urban/non-urban status. The urban/non-urban boundaries were defined so that the communities defined as 'urban' were large enough to guarantee an ISA general population sample size of at least 15 dwellings.

In the stratum eligible for ISA, the two surveys partially shared their samples. In the non-urban strata, geographic clusters were selected at the first stage of sampling with probability proportional to their 16 to 65 year-old population. At the second stage, dwellings were selected in two phases. First, a sample of dwellings was selected with probability proportional to the anticipated number of 16 to 65 year-old household members. The ISA sample of individuals was selected from these dwellings. A subsample of these dwellings was then selected using a systematic sampling scheme to constitute the LISA sample. All members of the households residing in this final sample of dwellings became members of the LISA sample and formed the subsample called LISA/ISA. In urban strata, the sample design differed only in that there was no geographical clustering.

In the stratum ineligible for ISA, the provincial and urban/non-urban stratification and the geographic clustering were identical to that described above. The selection of dwellings in this stratum, however, was done in only one phase using simple systematic sampling. Again, all members of the households in the selected dwellings became members of the LISA sample and formed the LISA-only sample.

Data sources

Data collection for this reference period: 2011-11-01 to 2012-06-27

Responding to this survey is voluntary.

Data are collected directly from survey respondents and extracted from administrative files.

Data are collected by interviewers via a Computer Assisted Personal Interview, using the Caseman application.

Initial contact is in-person. Proxy responding is not permitted.

Data are also linked to the T1 Personal Master File, T4 Summary and Supplementary Files, Pension Plan in Canada Files, the T1 Family File, and the Immigration Database. Linkages to the tax files are done by using the respondent's personal identifiers and marital status to locate his/her SIN, which is then used to link to the tax sources.

View the Questionnaire(s) and reporting guide(s).

Error detection

Responses to survey questions are captured directly by interviewers using a computerized questionnaire. This reduces processing time and costs associated with data entry, transcription errors and data transmission.

Some editing of data is done directly at the time of the interview. Specifically, where a particular response appears to be inconsistent with previous answers or outside of expected values, message screens on the computer prompt the interviewer to confirm answers with the respondent, and, if necessary, to modify the information.

Once the data are received at head office, they are processed through a series of steps to convert the questionnaire responses from their initial raw format to a high-quality, user-friendly database involving a comprehensive set of variables for analysis.

Quality evaluation

Quality assurance measures were implemented at every collection and processing step. Measures included the recruitment of qualified interviewers, training provided to interviewers for specific survey concepts and procedures, observations of interviews to correct questionnaire design problems and instruction misinterpretations, procedures to ensure that data capture and coding errors were minimized, and edit quality checks to verify the processing logic. Data are verified to ensure internal consistency and are also compared to other sources.

Disclosure control

Statistics Canada is prohibited by law from releasing any information it collects which could identify any person, business, or organization, unless consent has been given by the respondent or as permitted by the Statistics Act. Various confidentiality rules are applied to all data that are released or published to prevent the publication or disclosure of any information deemed confidential. If necessary, data are suppressed to prevent direct or residual disclosure of identifiable data.

Once processing is complete, all personal identifiers are removed from the file. That file will be held indefinitely by the Income Statistics Division.

All personal identifiers required to link to tax files will be retained for the life of the survey's processing, but are only accessible to those directly involved in processing. Once the processing lifecycle is complete, the file is deleted.

Revisions and seasonal adjustment

This methodology does not apply to this survey.

Data accuracy

The reliability of survey estimates depends on the combined impact of non-sampling and sampling errors, and as in any other survey, the LISA estimates are subject to both types of errors.

Non-sampling errors can occur at any point in the collection and processing of the survey data. They take the form of coverage errors, non-response errors, response errors, capture errors, coding errors and other types of processing errors. Over a large number of observations, randomly occurring non-sampling errors will have a minimal impact on survey estimates. On the other hand, systematically occurring errors will contribute to biases in the survey estimates and can therefore have an impact on the reliability of the estimates. Considerable time and effort is invested into reducing non-sampling errors in the LISA.

Coverage error arises when sampling frame units do not exactly represent the target population. This may include omissions (under-coverage), or erroneous inclusions (over-coverage), or inclusion of units more than once (duplicates). Slippage is a measure of survey coverage error. It is defined as the percentage difference between control totals (coming from Census projections and/or other sources) and pre-calibrated weighted sample counts. In 2012, LISA observed some under-coverage reflected by slippage rates of 13.0% for the entire population, 13.6% for the population 15 years of age and older and 14.1% for the population 16 to 65 years of age. To reduce the coverage error the LISA weights are adjusted through calibration to reflect the control totals.

A major source of non-sampling errors in surveys is the effect of non-response on survey results. Non-response varies from partial non-response (failure to answer one or a few questions) to total non-response (refusal to participate or inability to contact the selected unit). In the LISA, imputation is performed strictly for missing income data. The overall income imputation rate for persons 15 years of age and older, was 16.5%. Any other missing data collected through the questionnaire remains missing when the data is released.

Total non-response was handled by adjusting the weight of persons who responded to the survey to compensate for those who did not respond. The overall household-level response rate for the 2012 LISA was 72.0%. Within responding households, the overall person-level response rate was 89.0%.

Response and capture errors are minimized by including edits in the data collection application. Training and reference manuals are also provided to the interviewers to ensure that the concepts used are well understood and interpreted during collection.

Sampling errors occur because inferences about the survey population are based on data from a sample of that population rather than the entire population. The sample design, the variability of the characteristic being measured, and the sample size all contribute to the magnitude of the sampling error. The standard error is a common measure of sampling error. The standard errors for the LISA are estimated using the bootstrap method. The coefficient of variation (CV) is the standard error expressed as a percentage of the estimate. The LISA CVs for estimates of key variables are available in the Data Quality Report.