Adult skills

Updated: 10 December 2024

Next update: Not yet determined

Share of adults with very good literacy skills

2023

20.0

Percentage of adults at each proficiency level in litreracy, numeracy and adaptive problemsolving. Per cent
	Literacy	Numeracy	Adaptive problemsolving
	2023
Less than level 1	6.4	4.4	4.4
Level 1	8.5	9.1	10.7
Level 2	24.3	24.8	34.5
Level 3	40.7	39.3	41.4
Level 4-5	20.0	22.4	8.9

Explanation of symbols

Source

StatBank source table 14466

Selected tables and charts from this statistics

Table 1Adult skills, by domain, proficiency level and gender. Per cent

Adult skills, by domain, proficiency level and gender. Per cent
	Literacy	Numeracy	Adaptive problemsolving
	2023
Both sexes
Less than level 1	6.4	4.4	4.4
Level 1	8.5	9.1	10.7
Level 2	24.3	24.8	34.5
Level 3	40.7	39.3	41.4
Level 4-5	20.0	22.4	8.9
Females
Less than level 1	5.5	3.9	3.5
Level 1	7.3	9.8	10.6
Level 2	24.7	28.8	37.1
Level 3	43.0	40.6	41.7
Level 4-5	19.5	16.9	7.1
Males
Less than level 1	7.3	4.8	5.3
Level 1	9.6	8.5	10.9
Level 2	24.0	20.9	32.1
Level 3	38.6	38.0	41.1
Level 4-5	20.5	27.7	10.6

Explanation of symbols

Source

StatBank source table 14466

Table 2Adult skills, by proficiency level and age. Per cent

Adult skills, by proficiency level and age. Per cent
	Literacy	Numeracy	Adaptive problemsolving
	2023
16-65 years
Less than level 1	6.4	4.4	4.4
Level 1	8.5	9.1	10.7
Level 2	24.3	24.8	34.5
Level 3	40.7	39.3	41.4
Level 4-5	20.0	22.4	8.9
16-24 years
Less than level 1	2.5	2.2	2.0
Level 1	7.6	8.0	6.4
Level 2	26.1	27.3	35.7
Level 3	43.3	42.2	45.6
Level 4-5	20.6	20.3	10.3
25-34 years
Less than level 1	6.4	3.9	3.4
Level 1	6.1	6.9	7.9
Level 2	18.2	20.8	26.0
Level 3	44.0	40.4	49.6
Level 4-5	25.3	28.0	13.1
35-44 years
Less than level 1	7.7	5.2	5.1
Level 1	8.1	7.8	9.4
Level 2	19.8	20.9	29.0
Level 3	39.4	39.4	44.9
Level 4-5	25.0	26.7	11.6
45-54 years
Less than level 1	8.4	5.7	6.2
Level 1	7.5	9.5	10.3
Level 2	23.8	23.4	36.1
Level 3	40.6	38.6	39.9
Level 4-5	19.8	22.9	7.5
55-65 years
Less than level 1	6.5	4.6	5.0
Level 1	12.9	13.0	18.7
Level 2	34.0	31.9	45.9
Level 3	36.9	36.5	27.9
Level 4-5	9.7	14.0	2.4

Explanation of symbols

Source

StatBank source table 14465

Table 3Adult skills, by proficiency level and educational attainment. Per cent

Adult skills, by proficiency level and educational attainment. Per cent
	Literacy	Numeracy	Adaptive problemsolving
	2023
All education levels
Less than level 1	6.4	4.4	4.4
Level 1	8.5	9.1	10.7
Level 2	24.3	24.8	34.5
Level 3	40.7	39.3	41.4
Level 4-5	20.0	22.4	8.9
Below upper secondary or none
Less than level 1	15.8	12.0	11.7
Level 1	17.6	19.0	18.7
Level 2	30.6	33.1	37.6
Level 3	29.7	28.6	28.4
Level 4-5	6.3	7.3	3.6
Upper secondary education
Less than level 1	5.8	4.1	4.2
Level 1	9.2	10.5	12.8
Level 2	32.2	31.5	42.0
Level 3	40.3	40.3	35.3
Level 4-5	12.6	13.6	5.8
Tertiary education
Less than level 1	2.5	1.0	1.3
Level 1	4.0	3.8	5.5
Level 2	16.1	16.4	27.9
Level 3	46.0	43.3	51.8
Level 4-5	31.4	35.5	13.5

Explanation of symbols

Source

StatBank source table 14467

Table 4Adult skills, by proficiency level and immigration category. Per cent

Adult skills, by proficiency level and immigration category. Per cent
	Literacy	Numeracy	Adaptive problemsolving
	2023
Total
Less than level 1	6.4	4.4	4.4
Level 1	8.5	9.1	10.7
Level 2	24.3	24.8	34.5
Level 3	40.7	39.3	41.4
Level 4-5	20.0	22.4	8.9
Immigrants
Less than level 1	25.7	16.9	17.5
Level 1	18.7	19.9	23.3
Level 2	24.9	24.5	30.8
Level 3	22.6	25.2	24.5
Level 4-5	8.1	13.5	3.9
Norwegian-born to immigrant parents
Less than level 1	4.1	3.2	3.1
Level 1	11.1	14.9	10.7
Level 2	32.7	28.0	37.6
Level 3	36.9	37.8	39.8
Level 4-5	15.2	16.0	8.8
Other population
Less than level 1	1.1	0.9	0.8
Level 1	5.5	5.9	7.2
Level 2	24.0	24.8	35.5
Level 3	46.0	43.3	46.2
Level 4-5	23.5	25.1	10.3

Explanation of symbols

Source

StatBank source table 14468

More figures from this statistics

See complete overview in Statbank (6)

About the statistics

The statistics provide an overview of skills in literacy, numeracy, and adaptive problem solving among the population aged 16 to 65 years. It is based on the PIAAC survey (Programme for the International Assessment of Adult Competencies) conducted in 2012 and 2023.

The information under «About the statistics» was last updated 9 December 2024.

Definitions

Definitions of the main concepts and variables

Concepts and definitions in the PIAAC are in accordance with the demands set by OECD.

Literacy

Literacy is defined as the ability to access, understand, evaluate and reflect on written texts in order to achieve one’s goals, to develop one’s knowledge and potential, and to participate in society. Literacy encompasses a range of skills from the decoding of written words and sentences to the comprehension, interpretation and evaluation of complex texts. This is a basic skill for developing more advanced skills individually, and it is also important for the economic and social development of society. Literacy was mapped both in 2012 and in 2023.

Numeracy

Numeracy is the ability to access, use, reason critically with mathematical content, information and ideas represented in multiple ways in order to engage in and manage the mathematical demands of a range of situations in adult life. Numeracy describes the ability to handle different situations that require mathematical knowledge and demands the ability to solve problems using mathematical information. This is a basic skill in a time when people are facing an increasing amount and a broader spectrum of numerical and mathematical information in daily life. Numeracy was mapped both in 2012 and in 2023.

Adaptive problem solving

Adaptive problem solving is the ability to achieve one’s goals in a dynamic situation in which a method for solution is not immediately available. It requires engaging in cognitive and metacognitive processes to define the problem, search for information, and apply a solution in a variety of information environments and contexts. The capacity to flexibly adapt problem-solving strategies to different contexts and situations is an important skill, both privately and in the workplace. Adaptive problem solving was mapped in 2023.

Problem solving in technology-rich environments

The ability to use digital technology, communication tools and networks to acquire and evaluate information, communicate with others and perform practical tasks. The assessment focuses on the abilities to solve problems for personal, work and civic purposes by setting up appropriate goals and plans, and accessing and making use of information through computers and computer networks.

Skill levels

All skills are measured on a scale from 0 to 500, but it is important to note that these scales are distinct, and scores on the different skill scales should not be directly compared. The scale in each skill area is described based on the difficulty of the tasks placed at various points on the scale. The scales are divided into “skill levels” based on specific score thresholds: six levels for literacy and numeracy (below level 1 and levels 1 to 5) and five levels for adaptive problem-solving (below level 1 and levels 1 to 4).

Skill levels by score achieved (points)

Skill	Below level 1	Level 1	Level 2	Level 3	Level 4	Level 5
Literacy	175 or below	176 - 225	226 - 275	276 - 325	326 - 375	376 or more
Numeracy	175 or below	176 - 225	226 - 275	276 - 325	326 - 375	376 or more
Adaptive problem solving	175 or below	176 - 225	226 - 275	276 - 325	326 or more

Literacy

Level / range score	Description
Below level 1 (less then 176)	Most adults below Level 1 are able to process meaning at the sentence level. Given a series of sentences that increase in complexity, they can tell if a sentence does or does not make sense either in terms of plausibility in the real world (i.e. sentences describing events that can versus those that cannot happen), or in terms of the internal logic of the sentence (i.e. sentences that are meaningful versus those that are not). Most adults at this level are also able to read short, simple paragraphs and, at certain points in the text, tell which of two words makes the sentence meaningful and consistent with the rest of the passage. Finally, they can access single words or numbers in very short texts in order to answer simple and explicit questions. The texts below Level 1 are very short and include no or just a few familiar structuring devices such as titles or paragraph headers. They do not include any distracting information nor navigation devices specific to digital texts (e.g. menus, links or tabs). Tasks below Level 1 are simple and very explicit regarding what to do and how to do it. These tasks only require understanding at the sentence level or across two simple adjacent sentences. When the text involves more than one sentence, the task merely requires dealing with target information in the form of a single word or phrase.
Level 1 (176-225)	Adults at Level 1 are able to locate information on a page of text, find a relevant link from a website, and identify relevant text among multiple options when the relevant information is explicitly cued. They can understand the meaning of short texts, as well as the organisation of lists or multiple sections within a single page. The texts at Level 1 may be continuous, non-continuous or mixed and pertain to printed or digital environments. They typically include a single page with up to a few hundred words and little or no distracting information. Non-continuous texts may have a list structure (such as a web search engine results page) or include a small number of independent sections, possibly with pictorial illustrations or simple diagrams. Tasks at Level 1 involve simple questions providing some guidance as to what needs to be done and a single processing step. There is a direct, fairly obvious match between the question and target information in the text, although some tasks may require the examination of more than one piece of information.
Level 2 (226-275)	At Level 2, adults are able to access and understand information in longer texts with some distracting information. They can navigate within simple multi-page digital texts to access and identify target information from various parts of the text. They can understand by paraphrasing or making inferences, based on single or adjacent pieces of information. Adults at Level 2 can consider more than one criterion or constraint in selecting or generating a response. The texts at this level can include multiple paragraphs distributed over one long or a few short pages, including simple websites. Non-continuous texts may feature a two-dimension table or a simple flow diagram. Access to target information may require the use of signalling or navigation devices typical of longer print or digital texts. The texts may include some distracting information. Tasks and texts at this level sometimes deal with specific, possibly unfamiliar, situations. Tasks require respondents to perform indirect matches between the text and content information, sometimes based on lengthy instructions. Some task statements provide little guidance about how to perform the task. Task achievement often requires the test taker to either reason about one piece of information or to gather information across multiple processing cycles.
Level 3 (276-325)	Adults at Level 3 are able to construct meaning across larger chunks of text or perform multi-step operations in order to identify and formulate responses. They can identify, interpret or evaluate one or more pieces of information, often employing varying levels of inference. They can combine various processes (accessing, understanding and evaluating) if the task requires. Adults at this level can compare and evaluate multiple pieces of information from the text(s) based on their relevance or credibility. Texts at this level are often dense or lengthy, including continuous, non-continuous and mixed texts. Information may be distributed across multiple pages, sometimes arising from multiple sources that provide conflicting information. Understanding rhetorical structures and text signals becomes more central to successfully completing tasks, especially when dealing with complex digital texts that require navigation. The texts may include specific, possibly unfamiliar, vocabulary and argumentative structures. Competing information is often present and sometimes salient, though no more than the target information. Tasks require the respondent to identify, interpret or evaluate one or more pieces of information, and often require varying levels of inference. Tasks at Level 3 also often demand that the respondent disregard irrelevant or inappropriate text content to answer accurately. The most complex tasks at this level include lengthy or complex questions requiring the identification of multiple criteria, without clear guidance regarding what has to be done.
Level 4 (326-375)	At Level 4, adults can read long and dense texts presented on multiple pages in order to complete tasks that involve accessing, understanding, evaluating and reflecting on the text(s) contents and sources across multiple processing cycles. Adults at this level can infer what the task is asking for based on complex or implicit statements. Successful task completion often requires the production of knowledge-based inferences. Texts and tasks at Level 4 may deal with abstract and unfamiliar situations. They often feature both lengthy content and a large amount of distracting information, which is sometimes as prominent as the information required to complete the task. At this level, adults are able to reason based on intrinsically complex questions that share only indirect matches with the text content, and/or require taking into consideration several pieces of information dispersed throughout the materials. Tasks may require evaluating subtle evidence claims or persuasive discourse relationships. Conditional information is frequently present in tasks at this level and must be taken into consideration by the respondent. Response modes may involve assessing or sorting complex assertions.
Level 5 (376-500)	At Level 5, the assessment provides no direct information on what adults can do. This is mostly because feasibility concerns (especially with respect to testing time) precluded the inclusion of highly difficult tasks involving complex interrelated goal structures, very long or complex document sets, or tools containing highly complex texts (e.g. extensive catalogues, complex menu structures, or lists of unstructured results from search engines), which require advanced skills to access and process the information they contain. These tasks, however, form part of the construct of literacy in today's world, and future assessments aiming at a better coverage of the upper end of the proficiency scale may seek to include testing units tapping into literacy skills at Level 5. The characteristics of the most difficult tasks at Level 4 offer some insight into what might constitute proficiency at Level 5. Adults at Level 5 may be able to reason about the task itself, setting up reading goals based on complex and implicit requests. They can presumably search for and integrate information across multiple, dense texts containing distracting information in prominent positions. They are able to construct syntheses of similar and contrasting ideas or points of view; or evaluate evidence-based arguments and the reliability of unfamiliar information sources. Tasks at Level 5 may also require the application and evaluation of abstract ideas and relationships. Evaluating the reliability of evidentiary sources and selecting information which is not just topically relevant but also trustworthy may be key to achievement.

Numeracy

Level / range score	Description
Below level 1 (less then 176)	Adults performing below Level 1 demonstrate elementary whole number sense and can access and use mathematical knowledge to solve single-step problems, where the information is presented using images or simple structured information set in authentic, commonplace contexts with little or no text or distracting information. The mathematical content is non-formal and explicit. Adults at this level can: • count up to 20 objects that are displayed with varying degrees of organisation (i.e. randomly arranged, separated into groups or in an array) • sort events into chronological order • compare unordered lists of numbers to identify the largest number based on the whole-number component • locate data directly from a graph • perform addition and subtraction with small whole numbers.
Level 1 (176-225)	Adults at Level 1 demonstrate number sense involving whole numbers, decimals, and common fractions and percentages. They can access, act on and use mathematical information located in slightly more complex representations set in authentic contexts where the mathematical content is explicit and uses informal mathematical terminology with little text and minimal distracting information. They can devise simple strategies using one or two steps to determine the solution. Adults at this level can: • interpret simple spatial representations or a scale on a map • identify and extract information from a table or graphical representation or complete a simple wholenumber bar chart • identify the largest value in an unordered list, including comparing the decimal part of the number • interpret and perform basic arithmetic operations, including multiplication and division, with whole numbers, money and common whole number percentages such as 25% and 50%.
Level 2 (226-275)	Adults at Level 2 can access, act on and use mathematical information and evaluate simple claims, in tasks set in a variety of authentic contexts. They are able to interpret and use information presented in slightly more complex forms (e.g. doughnut charts, stacked bar graphs or linear scales) that includes more formal terminology and more distracting information. Adults at this level can carry out multi-step mathematical processes. Adults at this level can: • use dynamic applications to perform simple measurements, and access and sort data given in tables or interactive charts • apply simple proportional reasoning or solve problems satisfying up to two conditions • formulate processes and expressions to represent situations mathematically, including combining and linking information • use mathematical reasoning when reviewing and evaluating the validity of statements • estimate or perform calculations involving fractions, decimals, time, measurements and less common percentages or perform routine algorithms such as that used to generate the mean • substitute into and evaluate contexts involving authentic algebraic formulae • identify patterns within two-dimensional geometrical representations.
Level 3 (276-325)	Adults at Level 3 can access, act on, use, reflect on and evaluate authentic mathematical contexts. This requires making judgements about how to use the given information when developing a solution to a problem. The mathematical information may be less explicit, embedded in contexts that are not always commonplace, and use representations and terminology that are more formal and involve greater complexity. Adults at this level can complete tasks where mathematical processes require the application of two or more steps and where multiple conditions need to be satisfied. Tasks may also require the use, integration or manipulation of multiple data sources in order to undertake the mathematical analyses necessary for the specific task. Adults at this level can: • estimate or perform calculations with a wide range of whole numbers, decimals, percentages, fractions, and measurements, including the application of proportional reasoning • determine a missing value from a data set given the mean • recognise and use patterns (visual and numerical) to estimate values • reflect on and use mathematical reasoning when reviewing and evaluating the validity of conclusions drawn from data, including a limited set of related conditions or statements • evaluate claims and stated relationships using a variety of data sources • recognise a formulation using non-standard notation • use spatial-visualisation to analyse figures, including moving from three- to two-dimensional representations.
Level 4 (326-375)	Adults at Level 4 can use and apply a range of problem-solving strategies to access, analyse, reason and critically reflect on and evaluate a broad range of mathematical information that is often presented in unfamiliar contexts. Such information may not be presented in an explicit manner. Adults at this level can devise and implement strategies to solve multi-step problems. This may involve reasoning about how to integrate concepts from different mathematical content areas or applying more complex and formal mathematical procedures. Adults at this level can: • calculate and interpret rates and ratios • devise a strategy to compare large data sets • read and interpret multi-variate data presented in a single graph • analyse complex, authentic algebraic formulae to understand relationships between variables • reflect and reason mathematically to review and evaluate the validity of statistical or mathematical conclusions, claims or arguments while accommodating relevant conditions • formulate a problem so that the result will be at the required level of specificity to the context of the situation.
Level 5 (376-500)	Adults at Level 5 can use and apply problem-solving strategies to analyse, evaluate, reason and critically reflect on complex and formal mathematical information, including dynamic representations. They demonstrate an understanding of statistical concepts and can critically reflect on whether a data set can be used to support or refute a claim. Adults at this level can determine the most appropriate graphical representation for relational data sets.

Adaptive problem solving

Level / range score	Description
Below level 1 (less then 176)	Adults performing below Level 1 understand very simple static problems situated within a clearly structured environment. Problems contain no invisible elements, no irrelevant information that might distract from the core of the problem, and typically only require a single step to solve the problem. Adults at this proficiency level are able to engage in the basic cognitive processes required to solve problems if explicit support is given and if they are prompted to do so.
Level 1 (176-225)	Adults at Level 1 are able to understand simple problems, and develop and implement solutions to solve them. Problems contain a limited number of elements and little to no irrelevant information. Solutions at this level are simple and consist of a limited number of steps. Problems are embedded in a context that includes one or two sources of information and presents a single, explicitly defined goal. Adults at Level 1 engage in the following cognitive processes: • develop mental models of simple and clearly structured problems • understand connections between tasks and stimuli that are explicit and embedded in a well-structured environment • solve problems that do not change and thereby do not require adaptivity.
Level 2 (226-275)	Adults at Level 2 can identify and apply solutions that consist of several steps to problems that require one target variable to be considered in order to judge whether the problem has been solved. In dynamic problems that exhibit change, adults at this level can identify relevant information if they are prompted about specific aspects of the change or if changes are transparent, occur only one at a time, relate to a single problem feature and are easily accessible. Problems at this level are presented in well-structured environments and contain only a few information elements with direct relevance to the problem. Minor impasses may be introduced but these can be resolved easily by adjusting the initial problem-solving procedure. Adults at Level 2 engage in the following cognitive processes: • develop mental models for simple to moderately difficult problems and adapt these as needed • adequately react to changes that are presented in visible increments • adapt resolution strategies to changes in the problem statement and the environment if these changes are of low or moderate cognitive complexity. Adults at this level engage in the following metacognitive processes: • monitor progress towards a solution that consists of one specific goal • search for optimal solutions by evaluating alternative solution paths within a given problem environment of low to moderate complexity • reflect on the chosen solution strategy if an impasse occurs and when explicitly prompted to adapt.
Level 3 (276-325)	Adults at Level 3 understand problems that are either static but more complex, or have an average to high level of dynamics. They can solve problems with multiple constraints or problems that require the attainment of several goals in parallel. In problems that change and require them to adapt, they can deal with frequent and, to some extent, continuous changes. They discriminate between changes that are relevant and those that are less relevant or unrelated to the problem. Adults at this level can identify and apply multi-step solutions that integrate several important variables simultaneously and consider the impact of several problem elements on each other. In dynamically changing problems, they predict future developments in the problem situation based on information collected from past developments. They adapt their behaviour according to the predicted change. Adults at Level 3 engage in the following cognitive processes: • generate mental models for moderately to highly complex problems • actively search for solutions by continuously evaluating the information provided in the problem environment • distinguish between relevant and irrelevant information. Adults at this level engage in the following metacognitive processes: • monitor comprehension of the problem and the changes in the problem • monitor and evaluate progress towards the goal of the problem • search for solutions by setting sub-goals and evaluating alternative solutions to the problem • reflect on their approach to solving the problem and, if necessary, revise their strategy.
Level 4 (326-375)	Adults at Level 4 are able to define the nature of problems in ill-structured and information-rich contexts. They can integrate multiple sources of information and their interactions, identify and disregard irrelevant information, and formulate relevant cues. Adults at this level can identify and apply multi-step solutions to meet one or more complex goals. They adapt the problem-solving process to changes, even if these changes are not obvious, occur unexpectedly or require a major reevaluation of the problem. They are able to distinguish between relevant and irrelevant changes, predict future developments of the problem situation, and consider multiple criteria simultaneously to judge whether the solution process is likely to lead to success. Adults at Level 4 engage in the following cognitive processes: • develop complex mental models of problems by integrating information from multiple sources • establish connections between tasks and stimuli even if these connections are difficult to detect or contain complex interactions • develop strategies to reach several goals in parallel and implement multi-step solutions • continuously update their mental model, search strategies and solutions during problem solving. Adults at this level engage in the following metacognitive processes: • continuously reflect and monitor the problem-solving process even if the environment is complex and changes unexpectedly • constantly revisit and re-evaluate their mental model, the available information and goal attainment • show adequate and immediate reactions to change • cope with frequent and unpredictable change and adapt their solution strategy accordingly.

Standard classifications

In 2012, level of education is coded according to ISCED97. In 2023, we use ISCED2011. The statistics also use the Standard for classification of immigration categories.

Administrative information

Name and topic

Name: Adult skills
Topic: Education

Next update

Not yet determined

Responsible division

Division for Education and Culture Statistics

Regional level

Whole country

Frequency and timeliness

The PIAAC survey is conducted every 10 years. PIAAC2 was conducted between September 2022 and April 2023. PIAAC1 was conducted in Norway between August 2011 and April 2012.

International reporting

Data are delivered to the Organisation for Economic Co-operation and Development (OECD).

Microdata

Collected and revised data are stored securely by Statistics Norway in compliance with applicable legislation on data processing.

Statistics Norway can grant access to the source data (de-identified microdata) on which the statistics are based, for researchers and public authorities for the purposes of preparing statistical results and analyses until 2072. Access can be granted upon application and subject to conditions. Refer to the details about this at Access to data from Statistics Norway.

A public use file is also delivered to the OECD.

Background

Background and purpose

PIAAC is the largest international survey of adult skills, conducted in Norway in 2012 (PIAAC1) and in 2023 (PIAAC2). The purpose of the survey is to map the skill levels in the adult population by directly measuring skills, meaning that respondents solve tasks. In addition to test tasks, the PIAAC survey also includes a comprehensive questionnaire, which makes it possible to view skills in the context of various background variables, including work experience, education level, and different demographic characteristics. PIAAC2 also maps respondents’ personality factors through the Five-Factor Model (Big 5).

The fact that the survey is conducted every ten years has led to changes in what is measured and how. PIAAC2 measures skills in reading comprehension, numeracy, and adaptive problem-solving using digital testing. In PIAAC1, in addition to reading and numeracy, problem-solving in ICT environments was measured, and testing was conducted either on a PC or on paper. Reading and numeracy were also mapped in the predecessors to PIAAC, and Norway participated in both The Adult Literacy and Life Skills Survey (ALL) in 2003 and the second round of The International Adult Literacy Survey (SIALS) in 1998.

Users and applications

By providing the relevant authorities and other users with information about skills in the adult population, PIAAC contributes to the knowledge base for policy development both in Norway and at the international level. Key users include the ministries, international organisations, researchers, trade unions and media.

Equal treatment of users

No external users have access to statistics before they are released on ssb.no after at least three months’ advance notice in the release calendar. This is one of the most important principles in Statistics Norway for ensuring the equal treatment of users.

International results of the survey have been known to the Ministry of Education and Research and the Ministry for Labour and Social Inclusion had access to international results through their role in the international PIAAC Board of participating countries.

Coherence with other statistics

Not relevant

Legal authority

The statistics are developed, produced and disseminated pursuant to Act no. 32 of 21 June 2019 relating to official statistics and Statistics Norway (the Statistics Act).

EEA reference

Not relevant

Production

Population

PIAAC covers the adult population (aged 16 to 65), with the exception of persons living in institutions.

Data sources and sampling

The target population for PIAAC is residents aged 16 to 65. People without a residence and those living in collective housing units (such as healthcare institutions, prisons, military camps) are not included in the target population. To calculate the skill level in this group at the national level, each participating country must conduct a certain number of interviews. The minimum requirement in PIAAC2 varies between 4,000 and 5,000 completed interviews, depending on the number of sampling stages and the expected design effect. The sample size was calculated based on the minimum requirement and the expected response rate.

In PIAAC2, a main sample of 7,800 people was drawn. To ensure a sufficient number of respondents, an additional sample of 2,180 people was also drawn, which could be used if the main sample did not provide a sufficient number of interviews. The samples were drawn as simple random samples based on residents in the Population Register as of 01.06.2022. Since the data collection in PIAAC2 was to take place over several months, the sample was drawn based on age in the middle of the data collection period, namely age as of 31.12.2022. The entire reserve sample was included in the total sample.

In PIAAC1, a sample of 8,506 people was drawn, along with a reserve sample of 1,705 people. There was no need to use the reserve sample.

Collection of data, editing and estimations

The data collection for PIAAC2 was conducted from September 2022 to June 2023, while the field period for PIAAC1 was from August 2011 to May 2012. The PIAAC survey is multi-part. First, respondents are guided through an interview, and then they answer tasks. In PIAAC2, tasks were to be solved on a tablet. While the interview could be conducted in either Norwegian or English, the self-administered task section could only be completed in Norwegian. In PIAAC1, tasks were carried out using a PC and paper exercise booklets. For detailed information on data collection, see also the documentation reports for PIAAC1 and PIAAC2.

The background interview was divided into various themes, with questions about factors that can affect the skills measured by PIAAC:

A: Demographic information: Questions about the respondent’s age, gender, country of birth, parents’ country of birth, and which language(s) the respondent learned and speaks at home.

B: Education and organized training: Questions related to the respondent’s formal education – highest completed, field of study, etc., and non-formal training, such as courses and other organized training the respondent has undergone.

C: Labor market status: The respondent’s employment status at the time of the interview, previous career, etc.

D: Current job or business: Questions about the respondent’s current occupation and income, number of employees where the respondent works, type of employment contract, job tasks, etc.

E: Last job or business (not working but has worked in the last five years): Questions about the respondent’s last job, reasons for not working now, etc.

F: Skills used in current/last job: Questions related to the respondent’s use of literacy and numeracy skills in the job, as well as the use of ICT in the workplace.

G: Use of skills in everyday life: Questions about the respondent’s use of PCs and other digital devices (e.g., smartphones) outside of work.

H: Respondent’s activities at work: Questions about the respondent’s job tasks and autonomy in the workplace, the work environment, including teamwork, inclusion, problem-solving, etc.

I: Individual characteristics: Questions about the respondent’s attitudes and activities, including participation in volunteer work, satisfaction with life, general health status, etc.

J: Background information: Questions about the respondent’s parents/guardians, partner, children, childhood, parents’/guardians’ education, etc.

K (only in PIAAC2): Social and emotional dimensions: Questions about the respondent’s social and emotional skills, measured through personality traits such as openness to experience, emotional stability, etc.

PIAAC2, unlike previous surveys, also estimates skills among the part of the adult population that cannot participate in the survey due to language barriers. These respondents participated in a short interview, the doorstep interview, where information about gender, age, education, employment status, country of birth, and number of years residing in Norway was collected.

Once the questions in PIAAC2 are answered, respondents proceed to the task section. After an introduction and training in using the tablet, the respondent is asked to solve 16 initial tasks – eight in “reading comprehension” and eight in “numeracy.” The score on these tasks determines which of three paths the respondent follows: those who do not pass the initial test (path 1) only answer tasks that assess basic reading and numeracy skills, while those who score low (path 2) and those who score high (path 3) also answer tasks from two of the three skill areas. No respondents receive tasks from all three domains. The tasks vary in difficulty and are not necessarily the same for all respondents. This is because no one receives all the tasks, and also because tasks in reading and numeracy are adaptively designed. This means that if a task is answered correctly, the difficulty level of the next task is either the same or higher.

For each area, a skill score from 0 to 500 is calculated, reflecting a person’s skills in reading comprehension, numeracy, and adaptive problem-solving. This calculation is done using methods within Item Response Theory (IRT) and involves combining responses from the questionnaire and tasks to calculate the probability that respondents can solve tasks of varying difficulty.

For detailed information about the PIAAC questionnaire and tasks, as well as the calculation of task scores, see the PIAAC technical report for PIAAC1 and PIAAC2, available at http://www.oecd.org/site/piaac.

The net sample in PIAAC2 consists of 4,053 people, of whom 64 only completed the doorstep interview. Using Statistics Norway’s standard for calculating the response rate, the actual effect of the data collection is 43 percent. In PIAAC1, the response rate was 62 percent, and the net sample consisted of 5,128 people.

The sample is intended to reflect the population in terms of the distribution of age groups, gender, education level, and other background variables. However, not all individuals in a gross sample respond to the survey, which introduces biases. Weighting and calibration were used to adjust for the biases that arise. See the documentation report for each survey for a detailed description of the process.

Seasonal adjustment

Not relevant

Confidentiality

Interviewers and everyone who works at Statistics Norway have a duty of confidentiality. Statistics Norway has its own data protection officer.

Statistics Norway does not publish figures where there is a risk of identifying individual data about persons or households. Therefore, we do not publish results for groups with fewer than 60 observations.

More information can be found on Statistics Norway’s website under Methods in official statistics, in the ‘Confidentiality’ section.

Comparability over time and space

The content in the PIAAC, ALL, and IALS is harmonized prior to data collection, allowing for direct comparison of results between countries for each survey. Comparing results between surveys requires taking into account changes in measurement instruments, implementation methods, and modeling of non-response. However, it is important to emphasize that the skills required in today’s society have changed. For example, having good reading and numeracy skills today means something different than in the 1990s, as we now have to deal with digital texts and new information channels.

Comparison of results between PIAAC2 and PIAAC1

PIAAC2 also estimates skills among the part of the adult population that cannot participate in the survey due to language barriers, which was not done in previous surveys. To compare results from PIAAC1 and PIAAC2, the doorstep interviews must therefore be excluded from the PIAAC2 data. Additionally, PIAAC2 has introduced several methodological changes, such as comprehensive digital testing and the inclusion of basic tasks on the main scales, which contribute to increased uncertainty when comparing results from different surveys, cycles, or years. To compare scores in literacy and numeracy between PIAAC1 and PIAAC2, the so-called “linking error” must therefore be added to the standard error when comparing certain measures, such as the mean or percentile values. This does not apply when comparing differences in the number of points, because the uncertainties in two point values will cancel each other out when calculating the difference. The linking error between PIAAC1 and PIAAC2 is estimated to be 3.27 for reading comprehension and 2.95 for numeracy.

Comparison of results between PIAAC2 and the predecessors to PIAAC (IALS and ALL)

It is possible to compare skill results between PIAAC and previous surveys, but since there are no exact measures of linking error for IALS and ALL, it is assumed that the linking error is zero, which may lead to underestimating the uncertainty in the trend analysis.

Accuracy and reliability

Sources of error and uncertainty

PIAAC is a survey, and surveys can have different sources of error.

Errors can occur both during data collection and processing. Collecting data through a questionnaire allows for the inclusion of filters, so that questions are adapted to the respondent’s answers to previous questions, and error messages can be included if the interviewer enters answers that are not consistent with previous answers.

Collection errors can also arise if the respondent provides incorrect answers. This may be due to difficulties in recalling past events or misunderstandings of questions. The respondent may also give incorrect answers to questions if they are perceived as sensitive.

Processing errors are deviations between the value that is recorded and the value that is ultimately reported. Various checks have been conducted to identify and correct errors.

At the start of data collection for PIAAC2, there was an error in the exercise section that caused the exercises to take a very long time. We found that some respondents took over 4 hours to complete the survey. The length of time taken for the exercises may have affected the results for some respondents who spent a very long time. Some respondents had to interrupt the interview because they no longer had time available. A new version of the interview program was released on October 27, 2022, which reduced the time required for the exercises. After this, the average time for an interview was reduced to about 2 hours, which was what respondents were initially told.

Through sample surveys, we can estimate the skill level in a large group (the population) by measuring the level only in a smaller sample drawn from the population. This provides significant savings compared to conducting the measurement in the entire population, but at the same time, we get some uncertainty in the estimates. We can calculate this uncertainty when we know the probability that each unit in the population will be selected for the sample.

The method used to calculate an estimate is called an estimator. There are two important aspects of an estimator. First, the estimator should provide approximately the correct value with repeated attempts. This means it “hits the target” in the sense that with repeated sampling, the average value of the estimates will be centered around the true population value; the estimator is unbiased. Additionally, we need a measure of how much variation around the population value the estimates have with repeated sampling. This variation is the statistical uncertainty of the estimate, and the common measure is the standard error (SE) of the estimate. SE is defined as the estimated standard deviation of the estimator. SE thus indicates how much an estimate will, on average, deviate from the true value.

As an illustration: If we want to estimate the percentage of women, ( P_0 ), in a population of size ( N ). Assume the sample of size ( n ) is randomly drawn, meaning all units have the same probability ( n / N ) of being included in the sample. Let ( P ) be the percentage of women in the sample. Then ( P ) is an unbiased estimator for ( P_0 ) and the standard error is given by:

The estimation error we make is the difference between ( P ) and ( P_0 ). This is, of course, unknown, but we can provide an estimate, the margin of error, of how large it can be with a given probability. The margin of error is defined as 2· SE. The interval

( P – 2· SE , P + 2· SE )

is a 95 percent confidence interval. This means that the probability that the interval covers the true value P 0 is 0.95 (95 percent). In other words, with repeated sampling, 95 percent of the intervals will cover the true value P 0. We then say that there is 95 percent confidence that the calculated interval covers the true value.

Skill scores in PIAAC are calculated using methods within Item Response Theory (IRT), and like all estimates, they contain some uncertainty. The results in general, and the average scores in particular, should therefore always be shown with the corresponding standard error.

Revision

Not relevant