ISTAT – National Institute of Statistics

Population register, demographic and living conditions statistics - DCA

ISTAT

Division for population register, demographic and living conditions statistics (DCA)

Viale Liegi 13- 00198 Rome- Italy

The EU survey on the use of ICT in households and by individuals is an annual survey conducted since 2002. In Italy , it has been conducted since 2002.

In 2022, the survey collects data on the access to information and communication technologies (ICT), on the use of the internet, e-government, e-commerce, internet of things, as well as green ICT.

National language: Indagine multiscopo "Aspetti della vita quotidiana"

English: Multipurpose survey "Everyday life aspects"

The following common concepts and definitions apply under the Integrated European Social Statistics (IESS):

• the International Standard Classification of Education (ISCED) 2011 published in the following breakdowns: low (ISCED levels 0-2: no formal education, primary education or lower secondary education), medium (ISCED levels 3-4: upper secondary or post-secondary non-tertiary education) and high (ISCED levels 5-6: tertiary programmes which normally need a successful completion of ISCED 3 or 4, or second-stage tertiary education leading to an advanced research qualification);
• the International Standard Classification for Occupation ISCO-08 at the 2-digit level;
• the Classification of Economic Activities (NACE Rev.2-2008), at section level;
• the Common classification of territorial units for statistics (NUTS 1) – finer granularity of NUTS 2 is provided on optional basis by some Member states;
• the SCL - Geographical code list;
• information about household income is provided at lower level of detail. 

Additional classifications used in the national questionnaire: 

Territory (Codes for municipalities, provinces and regions)

The ICT survey in households and by individuals covers those households having at least one member in the age group 16 to 74 years old. Internet access of households refers to the percentage of households that have an internet access, so that anyone in the household could use the internet.

At national level are in the scope also Individuals younger than 16 and Individuals older than 74

The survey is collecting data of internet users, individuals who have used the internet in the three months prior to the survey. Regular internet users are individuals who used the internet, on average, at least once a week in the three months prior to the survey.

This annual survey is used to benchmark ICT-driven developments, both by following developments for core variables over time and by looking in greater depth at other aspects at a specific point in time. While the survey initially concentrated on access and connectivity issues, its scope has subsequently been extended to cover a variety of subjects (for example, the use of e-government and e-commerce) and socio-economic analysis (such as regional diversity, gender specificity, differences in age, education and the employment situation). The scope of the survey with respect to different technologies is also adapted so as to cover new product groups and means of delivering communication technologies to end-users.

For more details on the methodology applicable in each survey year, please consult the Methodological Manual for the respective year on CIRCABC - Methodological Manual - Information society statistics (europa.eu).

Deviations from standard ICT concepts: None

Households and Individuals

In the ICT usage survey, the target population for the different statistical units is:

- individuals: all individuals aged 16 to 74;

- households: all (private) households with at least one member aged 16 to 74. 

Target population composed of households and/or individuals:

• Number of households: 15 621 final sample, 21 626 746 universe  
• Number of individuals: 31 170 final sample, 43 612 281 universe

Non-compulsory age groups also included in the target population:

The whole Italian territory (no region excluded) except Vatican and San Marino State

Year 2022

Not applicable

Percentages of ‘Households’ and Percentages of ‘Individuals’

The main reference period for the ICT variables is the first quarter of the year

 The data collection period is 8 March 2022  to 21 May 2022 

The legal basis for the 2022 EU survey on the use of ICT in households and by individuals is the Regulation (EU) 2019/1700 of the European Parliament and of the Council of 10 October 2019 establishing a common framework for European statistics relating to persons and households, based on data at individual level collected from samples (OJ  L 261 I, 14.10.2019, p. 1), as implemented by the Commission Implementing Regulation (EU) 2021/1223 of 27 July 2021 specifying the technical items of the data set, establishing the technical formats for transmission of information and specifying the detailed arrangements and content of the quality reports on the organisation of a sample survey in the use of information and communication technologies domain for reference year 2022 pursuant to Regulation (EU) 2019/1700 of the European Parliament and of the Council (OJ L 2269, 27.07.2021, pp. 1-45).

Complementary national legislation constituting the legal basis for the survey on the use of ICT in households and by individuals: 

Decree of the President of the Republic of 9 March 2022 approving the National Statistical Program 2020- 2022 and the related list of surveys with mandatory response for private entities ( OJ General Series No 122 d of  26-05-2022 - S.O. No. n. 20)

Not applicable

The information collected, protected by statistical confidentiality (art. 9 Legislative Decree no. 322/1989) and subject to the regulations on the protection of personal data (Legislative Decree no. 196/2003). This information may be used, also for successive processing, by subjects of the Italian National Statistical System, exclusively for statistical purposes, and may be communicated for the purpose of scientific research according to the terms and by the procedures laid down in art. 7 of the Code of ethics for the processing of personal data performed in the context of the Italian National Statistical System (Annex A.3 of Legislative Decree no. 196/2003). The data will be disseminated in aggregate form so that it will not be possible to trace the data back to the individuals who provided them, ensuring the maximum privacy.

See for information in Italian: https://www.istat.it/it/censimenti/popolazione-e-abitazioni/normativa-e-privacy

Data are transmitted via Eurostat integrated environment for data transmission and delivered to a secure environment where they are treated. 

17 March 2023 (internal calendar)

The planned release dates are announced some weeks in advance on the ISTAT website  https://www.istat.it/it/informazioni-e-servizi/per-i-giornalisti/appuntamenti/calendario-diffusioni-ed-eventi.

ISTAT's dissemination policy, as well as other national statistical institutes, is inspired by principles of timeliness and transparency shared at international level and enunciated by supranational organizations such as the United Nations, the International Monetary Fund (IMF) and the European Commission.

Annual

Press Release is foreseen in March 2023

Noi Italia. 100 Statistics to understand the country we live  https://noi-italia.istat.it/#

The measurement of well being: https://www.istat.it/it/benessere-e-sostenibilit%C3%A0

Statistical report ICT use by citizens: https://www.istat.it/it/archivio/282257

Data dissemination in the data wharehouse I.Stat theme "Culture, communication, tourism" subtheme "Internet: access and type of use": http://dati.istat.it/?lang=en&SubSessionId=f57f860d-2784-45ec-9e5b-67780152b746

Not applicable

Information on microdata access are available at: https://www.istat.it/en/analysis-and-products/microdata-files

Files are released free of charge and in compliance with the principle of statistical secrecy and protection of personal data.

Four types of microdata will be released

• PUBLIC USE FILES, downloadable directly from the website;
• FILES FOR RESEARCH PURPOSES, issued to subjects belonging to universities or research bodies upon the presentation of a research project;
• FILES FOR SISTAN, accessible only by the statistical offices of the National Statistical System;
• FILES FOR THE LABORATORY, for Elementary Data Analysis (ADELE), where subjects belonging to universities or research bodies can access microdata files of all ISTAT surveys (without identification, sensitive and judicial data).

PUBLIC USE FILES 

Public use of mIcro.STAT files are collections of elementary data downloaded directly and free of charge from the ISTAT website. To acquire such files it is necessary to register at the area of the ISTAT website dedicated to them and to accept the terms of use. Data are available in different formats (TXT, STATA, SAS, R).

FILES FOR RESEARCH PURPOSES

Files for research purposes are developed in relation to statistical surveys regarding individuals and households as well as enterprises, and are created specifically for the purposes of scientific research. These files are subject to particular statistical treatments that limit the identifiability of the respondent, while maintaining a high level of detailed information.

Files for research purposes may be requested exclusively by:

• subjects belonging to universities or research bodies and institutions to which the “Ethical code for the processing of statistical data outside Sistan” applies;
• other subjects with Eurostat requirements defined for the provision of microdata files in accordance with Commission Regulation (EC) no. 557/2013.

Files are available both in delimited or fixed structure and are also provided with the programs to import these files in STATA, SAS and R.

To access microdata it is necessary that the requesting body is recognized as a research entity by the Comstat (Committee for Directing and Co-ordinating Statistical Information) on the basis of established criteria (Article 5-ter paragraph 1, letter a) of the legislative decree 14 March 2013, no. 33) or is included into the list of research entities recognized by Eurostat (Regulation (EU) No. 557/2013).

The researchers of an institution included in the list of recognized organizations may submit, for a preliminary assessment, the research proposal for the request for access to MFR files to: rilasciomicrodati@istat.it.

FILES FOR SISTAN

Requests for elementary data by Sistan departments

Directive no. 9 issued by Comstat (Committee for Directing and Co-ordinating Statistical Information), “Criteria and procedures concerning the communication of personal data within the National Statistical System”, brings Sistan fully into line with legislation concerning the protection of personal data (Legislative Decree 196/03 and ethical code of conduct). The directive deals with the transmission of previously collected personal data to a statistic bureau or agency or any other party in the System (in this specific case ISTAT) which requests them for statistical purposes.

Such requests may be made for the purpose of:

1. the implementation of the National Statistical Programme (PSN);
2. the execution of statistical data processes in connection with the institutional activities or local area of competence of the requesting party. In this case, a brief description of the project must be provided.

The transmission of personal data with information containing unique identification data must be limited to exceptional cases in which it is absolutely and strictly necessary (in which it is impossible to achieve established objectives without information for identification). The signer of the request assumes full responsibility with regard to the applicability of this condition.

In order to acquire information or microdata files the requesting party (Director of the Statistics Department or data controller/supervisor for public Bodies and Boards providing statistical information) must register at the Cont@ct center. Once registration has been completed, or for users already registered, the request must be formulated by selecting, in the Cont@ct centre the area: “Dati elementari per uffici Sistan” (Elementary data for Sistan departments) and filling in the online form.

FILES FOR THE LABORATORY

The Laboratory for Elementary Data Analysis (ADELE) is a “safe” environment in which researchers from universities or research institutions or bodies to which the Code of conduct and professional practice applying to processing of personal data for statistical and scientific purposes applies (Annex A.4, Legislative Decree no. 196 of 30th June 2003) may conduct statistical analyses that require the use of elementary data, where information already available with other tools is not sufficient (I.Stat data warehouse, publications, data tables, databases, microdata files, custom processing).

Within the Laboratory, data security and statistical confidentiality are guaranteed by the control of both the working methods and the results of the analyzes conducted by the users.

Once the processing is complete, the output is evaluated in terms of statistical confidentiality by the experts of the ADELE Laboratory. Only results that positively comply with the Rules for the release of results can be issued. Please note that starting from March 2016 the release rules for structural equation models and factor analysis have been specified and since June 2016 also for analysis in main components and correspondence analysis.

Access to the ADELE Laboratory is free.

Not applicable

Not applicable

It is possible to find Survey description in ISTAT information system on quality of statistical production processes https://siqual.istat.it/SIQual/visualizza.do?id=0058000

100%

The following methods are used to improve quality:

Prevention, monitoring and evaluation of total non-response: initiatives to encourage participation in the survey;  

Treatment of incorrect or incomplete responses: training and supervision of operators and verification of procedures; Interviewer training corrective methods to reduce the effects of incorrect or incomplete responses;

Validation of data: Coherence control with data from other surveys (Census of population, LFS) or other sources (Annual Report); Coherence control with previous data of the same survey.

- Initiatives to encourage participation in the survey. A few days before the interview, a letter is sent to the sampled households, signed by the President of ISTAT, in which the survey is presented. Furthermore all the people included in the sample could ask for information on the survey by calling a free telephone number (working from Monday to Friday from 9 a.m. to 1 p.m. and from 2 to 7 p.m.).

- Training and supervision of operators and verification of procedures

- A monitoring web system was implemented to allow a daily control of interviewer performance. The ISTAT personnel controlled daily the updating of the monitoring web system. The interviewers had to fill out daily the Monitoring Form to keep track of all contacts and interviews: number of contacts, provisional or final outcome of the interview, duration, date and time of the interview; non-response and reason for non-response; difficulty in contacts; etc. To ensure high-quality of the interviewers performance, the supervisors analyzed the quality indicators in order to take timely action in case of critical situations.

- Validation of data: consistency check with data from other surveys (Census, LFS) or other sources (Annual Report). Consistency check with previous data from the same survey.

For further information https://www.istat.it/en/methods-and-tools

The comprehensive monitoring system that involves the interviewers, the referent person of the municipalities, the regional offices and the central staff of ISTAT allowed to prevent and reduce non-response and/or measurement errors. The access to the online quality indicators from all persons involved in the monitoring, enabled us to follow daily the survey in its various aspects: the progress of the survey, the lack of participation and the reasons for not participating, the method of completion of the questionnaires, etc., allowing us to quickly identify and resolve critical situations highlighted by the system.

At European level, the recommended use of the annual Eurostat model questionnaire aims at improving comparability of the results among the countries that conduct the survey on ICT usage by household. Moreover, the Methodological Manual provides guidelines and clarifications for the implementation of the surveys in the Member States.

ISTAT uses working groups for the preparation of the National Statistical Program (PSN). The working group in which is included the ICT survey is responsible for meeting to analyze the supply and demand for statistical information for the PSN. The participants are from other public institutions or from private sector.

Not available

All of the variables required for transmission 2022 have been included in the microdata.

100%

The main sources of error of the estimates are sampling errors, nonresponse errors (unit and item) and measurement errors.

As regards the first ones, they were assessed with the standard error (SE) estimation; this is a measure of precision of the survey estimates. SE was estimated from the sample data through the linearization formula of the sampling variance (Re-genesees software) of the main estimates. 

Non-sampling errors are errors in survey estimates which cannot be attributed to sampling fluctuations. Such errors can either be coverage errors, measurement errors, non-response errors, processing errors or model assumption errors.

Non-sampling errors are basically of 4 types:1) Coverage errors: errors due to divergences existing between the target population and the sampling frame; 2) Measurement errors: errors that occur at the time of data collection. There are a number of sources for these errors such as the survey instrument, the information system, the interviewer and the mode of collection; 3) Processing errors: errors in post-data-collection processes such as data entry, keying, editing and weighting; 4) Non-response errors: errors due to an unsuccessful attempt to obtain the desired information from an eligible unit. Two main types of non-response errors are considered: Unit non-response - refers to absence of information of the whole units (households and/or persons) selected into the sample; Item non-response - refers to the situation where a sample unit has been successfully enumerated, but not all required information has been obtained.

Nonresponse errors due to unit non-response were monitored by indicators in order to prevent and reduce them. This was reached with actions made before the data collection started (interviewing technique to avoid refusals, letters to households) and after data collection, by using calibration estimators (this is also partially useful to compensate for under-coverage errors). Measurement errors and item nonresponse errors, which were monitored by indicators and reports, were corrected by control and editing procedures. Double data entry of a sample of record was used. Deterministic and stochastic imputations were used as previously described.

Coverage errors are errors that express the quantitative divergence between the sampling frame population and the target population due to, for example, remoteness, age, multiple entries; coverage of different sub-populations. The use of the Master Sample of Census from 2022 could reduce the risk of coverage errors because the list was previously corrected and controlled for Census.

As regard sampling errors, they were assessed with the standard error (SE) estimation, that is a measure of precision of the survey estimates. Standard errors are calculated using the Taylor linearization technique. The software used to calculate standard errors is ReGenesees (software produced by Istat https://www.istat.it/en/methods-and-tools/methods-and-it-tools/process/processing-tools/regenesees).

The coefficient of variation is given by the square root of the variance of the estimator out of its expected value. It is estimated by the ratio of the square root of the estimated sampling variance to the estimated value of the variable of interest. See document annexed below.

References in the literature:Deville J.C., Sarndal C.E. (1992) Calibration Estimators in Survey Sampling, Journal of the American Statistical Association, vol. 87, pp. 376-382 Woodruff, R. S. (1971), A Simple Method for Approximating the Variance of a Complicated Estimate, Journal of the American Statistical Association, vol. 66, pp. 411-414

Precision estimates for the question "Individuals having ordered goods or services for private use over the internet in the last 12 months" (individuals who ticked 'Within the last 3 months' or 'Between 3 months and a year ago' in question D1 of the 2022 model questionnaire):

Number of respondents (absolute value for ‘Yes’ answers):  15 138

Estimated proportion (in %):   49.30

Standard error (in percentage points): 0.25

Details of the breakdowns are available in the file INFOSOC_HHNSI_A_IT_2022_0000_an1 in the Annexes.

See more details on non-sampling error below.

The sampling frame populations are:

 - LAC (Liste Anagrafiche Comunali) - Register of households resident in municipalities updated at the 01 January 2020 for municipalities with less than 1,000 inhabitants;

 - Master Sample of CENSUS 2022 - List of municipalities and households used for the permanent Census for municipalities with more than 1,000 inhabitants.

Those sampling frames might contain errors for information such as addresses (due for instance to recent change of the address), wrong inclusions (recent emigration) and missed inclusions (recent immigration). 

Coverage errors could be also due to the time lag between last update of the sampling frame and the time of the actual sampling (few months for LAC, one year for CENSUS 2021).

The use of the Master Sample of Census 2022 reduces the risk of coverage errors because the list was previously corrected and controlled for Census.

Not applicable

Not requested in the ICT survey.

1)       Measurement errors:  

The main measurement errors occurred during data collection were related to the use of the PAPI technique. In particular, the use of paper made difficult to manage some filters and errors on codification of variables. 

2)       Questionnaire design and testing:  

The ICT HH questionnaire is based on the design of the questionnaire recommended by Eurostat. The module on ICT usage in households and by individuals is embedded in the annual multipurpose survey “Aspects of Daily life” integrating some sections with a few other questions useful at national level and every year ISTAT experts in the preparation of questionnaires work on the optimization of the questionnaire and testing of the CAWI and CAPI questionnaire.

3)       Interviewer training: 

Interviewers are recruited by the Statistical Offices of the Municipalities complying with the requirements provided by the National Statistical Institute (ISTAT). Some interviewers had experience in previous social surveys (they are registered in a register of interviewers that includes quality indicators on their performance) and others were trained for the first time. The personnel of the regional offices of ISTAT trained both the municipal contact persons for the survey and the interviewers. The staff of multipurpose survey “Aspects of Daily life”, trained the colleagues of the ISTAT regional offices, who have a long experience in carrying out sample surveys and in coordinating the activities of the interviewers.

The training of the interviewers was generally face to face in a classroom, but in these last two years because of the Covid-19 pandemic, the training has been done online. The training documents were: slides, questionnaires and guidelines. Interviewers received a login and a password to access the web monitoring system of the survey, the slides, the questionnaires and the manual with the guidelines. The guidelines explained how to contact the household for the interviews; how to behave to ensure the cooperation and the participation to the survey of the members of the household; how to carry out the interview; the rules to comply with for proxies and privacy issues; detailed information for each variable of the questionnaire.

4)       Proxy interview rates: 8.91%

Information about non-respondents:  The distribution by sex and age of non-respondents did not have high bias compared to the respondent one. 

The unit response rate is the ratio of the number of in-scope respondents (= the number of achieved interviews or the net sample size to the number of eligible elements selected from the sampling frame).

Unit non-response rate for

• Households:   24.4%
• Individuals (aged 16-74):   24.4%

Comments: 

Net sample size or final sample HH  [15 621] = Number of eligible elements - Non-contact (2 934) - Refusal (1 161) - Other non-response (949)

Net sample size or final sample IND [31 170] = Number of eligible elements (41 235) - Non-contact (5 854) - Refusal (2 317) - Other non-response (1 894)

1)  Methods used for dealing with unit non-response: 

The procedure used to construct the final weights to be assigned to the corresponding sample units, is generally divided into the following phases:

• the direct weights are calculated as reciprocal of the probability of inclusion of the units in the sample;
• the correction factors for total non-response are calculated by the inverse of the response rate in appropriate subsets of units;
• the base weights, or weights correct for total non-response, are obtained multiplying the direct weights by the non-response factors;
• the calibration correction factors are computed to satisfy at regional level the condition of equality between the known totals of some auxiliary variables and the corresponding sample estimates;
• the final weights are calculated by the product of the base weights and the correction factors obtained in step 3.

2)  Methods used for minimizing unit non-response:  

• Advance notification in form of letters
• Free phone number to contact and ask for information
• Assurances provided to the households by the interviewer and ISTAT staff regarding the confidentiality of information and the protection of privacy.

3)   Substitution permitted: 

If a household member is absent will be requested within the time period of the survey; only if this is not really possible then another household member will be interviewed. Proxy interviews are also allowed, in case of obvious difficulties of the component to respond (disability, special distress, illness). In case of proxy answers, the following guidelines are adopted. 

- if it is a couple with or without children, it is preferable to ask the questions to the woman of the couple

- if it is a single parent with children it is preferable to ask the questions to the parent in other situations another adult in the household who can provide the information

4)   Substitution rate: 8.9 %   

Items with low response rates (observed rates in %):  

In the Module on Green ICT, to the question "What did you do with any of the following devices when you replaced or were no longer using them? For each item, please refer to your personal, most recent device that you replaced/no longer use)", the following items showed low reponse rates:  

ECO_DLT (LAPTOP OR TABLET) = 78.24% 

ECO_DPC (DESKTOP COMPUTER) = 79.35%

Data entry is performed by a private company contracted by ISTAT. A format, reporting for each variable the admitted values and warnings (outliers), was prepared by ISTAT to ensure that all variables were correctly filled out throughout a software used for data entry by the private company.

Check of the coherence between the electronic dataset and the paper questionnaire was carried out by controlling the files after the data entry: coding errors (e.g. municipality codes), data entry errors (e.g. a one digit  number instead of a two digit number), data out of possible range or incoherence of data (e.g. the age calculated by the date of birth and the age in years, the marital status not coherent with other information like the year of the marriage, or the other information concerning the family).

Check and deterministic correction of all variable were done in order to correct incoherent values and errors. The validation rules were implemented in SAS programs for all the modules.

Imputations were applied to respect all the ICT validation rules and treatment of errors concerning the 1) Not admitted values; 2) Outliers; 3) Missing values; 4) Incoherent values among variables in the same module or in different modules.

The core social variables (age, sex, legal marital status, de facto marital status, type of household) and level of education, labour status, were checked in order to correct incoherent values and impute missing values.

Other National datasets (surveys or administrative registers) concerning the same dimensions /questions or phenomena were used to validate/compare the variables.

Not requested for ICT Survey

7 December 2022

Data have been submitted to Eurostat 7 December  2022

37  days

Geographical comparability is ensured by the sampling design that was carried out ensuring the representativeness of the data at the regional level.

Concerning the differences between the statistical process and the EU regulation and guidelines it is important to consider:

In the ISTAT sample surveys households' members are identified according to

1. the usual residence in the dwelling and
2. the marriage, kinship, affinity, adoption, patronage and affection ties.

Not relevant

Possible limitations in the use of data for comparisons over time:  

Not relevant

The length of comparable time series depends on the module and variable considered within each of the modules of the survey.

Not applicable

Not applicable

Not applicable

All statistics are coherent within the dataset

MANDATORY questions in the Eurostat model questionnaire 2022:

Table 15.4.1. in the file INFOSOC_HHNSI_A_IT_2022_0000_an1 in the Annexes lists the questions that do not reflect the coverage of subjects and characteristics of Annex 2 of the Commission Delegated Regulation (EU) 2021/1898 of the 20 July 2021. 

Adoption of OPTIONAL questions and items in the Eurostat model questionnaire 2022:

Table 15.4.2. in the file INFOSOC_HHNSI_A_IT_2022_0000_an1 in the Annexes lists the optional questions from the annual Eurostat model questionnaire 2022 included in the national questionnaire and their coverage for age groups beyond the standard scope. 

Additional questions introduced in the national questionnaire:  none

Effects of deviations from the routing used in the Eurostat model questionnaire:  No deviations from Eurostat’s routing otherwise

There are no revisions to report

No revision to report

Not relevant

The source of the raw data is described with more details in the paragraphs below.

For municipalities with 1,000 inhabitants or more: Master Sample of CENSUS - List of municipalities and households used for the permanent Census;

For municipalities with less than 1,000 inhabitants: LAC (Liste Anagrafiche Comunali) - Register of households resident in municipalities.

Survey vehicle: The module on ICT usage in households and by individuals is embedded in the annual multipurpose survey “Aspects of Daily life” that is the main survey of ISTAT’s integrated system of multi-purpose social surveys. This annual survey is the supporting and normalising element of the whole social informative framework. It collects a set of data concerning individuals, households and events which affords to construct and analyse the citizen’s demand, besides comparing it with services supply, already surveyed by ISTAT.

Survey participation: Participation in this survey is mandatory because it is part of the National Statistical Plan.

The sample is selected from the Master sample of the permanent census and from LAC (Liste Anagrafiche Comunali). In the first stage were extracted 800  municipalities at the second stage, households were randomly selected. 

The sampling design is a probability design.

The sample is systematic selected with probabilities proportional-to-size.

Around 230 primary sampling units are self-representing, defined according to a threshold which is function of the sampling fraction at NUTS2 level and the minimum number of sampling households for municipality.

Households are second stage sampling units and are selected for each municipality from the theoretical sample of master sample with equal probabilities.

All individuals in the selected household are interviewed.

Annual

1) Methods used to gather data: 

Mix mode 

 64.53% Paper assisted personal interview (PAPI)) and self-administered paper questionnaire.  35.47%  Computer assisted web interview (CAWI)

2) Short description of the survey method:

The information is collected through a mixed technique, which uses an online questionnaire that is filled in by respondents (CAWI technique, Computer-Assisted Web Interviewing) or a direct interview with electronic questionnaire administered by an interviewer (CAPI technique, Computer-Assisted Personal Interviewing) and self-administered paper questionnaire.

3) Variables completed from an external source:

In instances where there was no response on some demographic variables (sex, year of birth, citizenship), information was completed by Register of households resident in municipalities. 

The procedures used for checking and validating the source data are :

• Internal consistency of data analysis
• Time series comparison
• Acquisition of information on data processing, controls and/or corrections
• Comparison with external sources (statistical registers, other sources)
• Validation standards provided by Eurostat.

Data entry is performed by a private company contracted by ISTAT. A format, reporting for each variable the admitted values and warnings (outliers), was prepared by ISTAT to ensure that all variables were correctly filled out throughout a software used for data entry by the private company.

Check of the coherence between the electronic dataset and the paper questionnaire was carried out by controlling the files after the data entry: coding errors (e.g. municipality codes), data entry errors (e.g. a one digit  number instead of a two digit number), data out of possible range or incoherence of data (e.g. the age calculated by the date of birth and the age in years, the marital status not coherent with other information like the year of the marriage, or the other information concerning the family).

Check and deterministic correction of all variable were done in order to correct incoherent values and errors. Validation rules were implemented in SAS programs for all the modules.

Imputations were applied to respect all validation rules and treatment of errors concerning the 1) Not admitted values; 2) Outliers; 3) Missing values; 4) Incoherent values among variables in the same module or in different modules. The core social variables (age, sex, legal marital status, de facto marital status, type of household) and level of education, labour status, were checked in order to correct incoherent values and impute missing values. Other National datasets (surveys or administrative registers) concerning the same dimensions /questions or phenomena were used to validate/compare the variables.

Data are checked and corrected following to different approaches: deterministic imputation based on if then conditions to ensure internal coherence of data (plan of check) and probabilistic imputation to deal with partial non response (Fellegi-Holt methodology or nearest-neighbour imputation).  

Calibration estimator are used the corrections to the design weights

For the target indicator "Individuals having ordered goods or services for private use over the internet in the last 12 months" (individuals who ticked 'Within the last 3 months' or 'Between 3 months and a year ago' in question D1 of the 2022 model questionnaire):

Imputation rate (% of observations):1.65

Imputation rate (share of estimate):2.13

Methods used to impute item non-response: 

Random imputation

Grossing up procedures have been applied to: Individuals and/or Households

 The estimates produced by the survey are absolute and relative frequencies, referring to the households and to persons or estimates of quantitative variables. The principle on which each sample estimation method is based is that the units belonging to the sample represent also the units of the population that are not included in the sample. This principle is achieved by attributing a sample unit to a weight that indicates the number of units of the population represented by the unit itself. For example, if a sample analysis is assigned a weight of 30, this indicates that the units are not included in the sample. The weights are obtained by means of a calibration estimator.

Description of the weighting procedures:

The procedure used to construct the final weights to be assigned to the corresponding sample units, is generally divided into the following phases:

1. the direct weights are calculated as reciprocal of the probability of inclusion of the units in the sample;
2. the calibration correction factors are computed to satisfy at regional level the condition of equality between the known totals of some auxiliary variables and the corresponding sample estimates;
3. the final weights are calculated by the product of the base weights and the correction factors obtained in step 2.

Not relevant

Not relevant