About the survey
Definitions of literacy
The International Adult Literacy Survey Database (IALS) was a seven-country initiative
conducted in the fall of 1994. Its goal: to create comparable literacy profiles
across national, linguistic and cultural boundaries. The survey also offers
the world’s only source of comparative data on participation in adult
education and training. The results, published in the report Literacy, Economy
and Society: Results of the first International Adult Literacy Survey Database (Organisation
for Economic Co-operation and Development and Statistics Canada 1995), demonstrated
a strong plausible link between literacy and a country’s economic potential.
A second and a third round of data collection of IALS were conducted in 1996
(See Literacy Skills for the Knowledge Society: Further results on the International Adult Literacy Survey Database (OECD and Human Resources Development Canada, 1997))
and in 1998 (See Literacy in the Information Age: Final Report on the International Adult Literacy Survey Database (OECD and Statistics Canada, 2000)). In total, IALS includes
data pertaining to 23 countries or regions around the world.
Switzerland (French cantons)
Switzerland (German cantons)
Switzerland (Italian cantons)
Definitions of literacy
Literacy profiles can be computed for each of the three different domains listed
Prose literacy — the knowledge and skills needed to
understand and use
information from texts including editorials, news stories, poems and fiction;
Document literacy — the knowledge and skills required
to locate and use
information contained in various formats, including job applications,
payroll forms, transportation schedules, maps, tables and graphics
and Quantitative literacy — the knowledge and skills
required to apply
arithmetic operations, either alone or sequentially, to numbers embedded
in printed materials, such as balancing a cheque book, figuring out a tip,
completing an order form or determining the amount of interest on a loan
from an advertisement.
The scores range on a scale from 0 to 500 points for each domain. Each of
the scales are split into five different levels from level 1 for the lowest
literacy proficiency to level 5 the strongest level of literacy proficiency.
The table below gives a detailed definition of each of these levels of proficiency
for each of the scales.
Description of the prose, document, and
quantitative literacy levels
(0 to 225)
the tasks at this level require the reader to locate one piece of information
in the text that is identical or synonymous to the information given in
the directive. If a plausible incorrect answer is present in the text, it
tends not to be near the correct information.
the tasks at this level require the reader to locate a piece of information
based on a literal match. Distracting information, if present, is typically
located away from the correct answer. Some tasks may direct the reader to
enter personal information onto a form.
no quantitative tasks used in the IALS fall below the score value of 225,
experience suggests that such tasks would require the reader to perform
a single, relatively simple operation (usually addition) for which either
the numbers are already entered onto the given document and the operation
is stipulated, or the numbers are provided and the operation does not require
the reader to borrow.
(226 to 275)
at this level tend to require the reader to locate one or more pieces of
information in the text, but several distractors may be present, or low-level
inferences may be required. Tasks at this level also begin to ask readers
to integrate two or more pieces of information, or to compare and contrast
tasks at this level are a bit more varied. While some still require the
reader to match on a single feature, more distracting information may be
present or the match may require a low-level inference. Some tasks at this
level may require the reader to enter information onto a form or to cycle
through information in a document.
in this level typically require readers to perform a single arithmetic operation
(frequently addition or subtraction) using numbers that are easily located
in the text or document. The operation to be performed may be easily inferred
from the wording of the question or the format of the material (for example,
a bank deposit form or an order form).
(276 to 325)
at this level tend to direct readers to search texts to match information
that require low-level inferences or that meet specified conditions. Sometimes
the reader is required to identify several pieces of information that are
located in different sentences or paragraphs rather than in a single sentence.
Readers may also be asked to integrate or to compare and contrast information
across paragraphs or sections of text.
at this level appear to be most varied. Some require the reader to make
literal or synonymous matches, but usually the matches require the reader
to take conditional information into account or to match on multiple features
of information. Some tasks at this level require the reader to integrate
information from one or more displays of information. Other tasks ask the
reader to cycle through a document to provide multiple responses.
found in this level typically require the reader to perform a single operation.
However, the operations become more variedsome multiplication and
division tasks are found in this level. Sometimes two or more numbers are
needed to solve the problem and the numbers are frequently embedded in more
complex displays. While semantic relation terms such as "how many"
or "calculate the difference" are often used, some of the tasks
require the reader to make higher order inferences to determine the appropriate
(326 to 375)
tasks require readers to perform multiple-feature matching or to provide
several responses where the requested information must be identified through
text-based inferences. Tasks at this level may also require the reader to
integrate or contrast pieces of information, sometimes presented in relatively
lengthy texts. Typically, these texts contain more distracting information
and the information that is requested is more abstract.
at this level, like those in the previous levels, ask the reader to match
on multiple features of information, to cycle through documents, and to
integrate information; frequently however, these tasks require the reader
to make higher order inferences to arrive at the correct answer. Sometimes,
conditional information is present in the document, which must be taken
into account by the reader.
exception, the tasks at this level require the reader to perform a single
arithmetic operation where typically either the quantities or the operation
are not easily determined. That is, for most of the tasks at this level,
the question or directive does not provide a semantic relation term such
as "how many" or "calculate the difference" to help
(376 to 500)
at this level require the reader to search for information in dense text
that contains a number of plausible distractors. Some require readers to
make high-level inferences or use specialized knowledge.
at this level require the reader to search through complex displays of information
that contain multiple distractors, to make high-level inferences, process
conditional information, or use specialized knowledge.
tasks require readers to perform multiple operations sequentially, and they
must disembed the features of the problem from the material provided or
rely on background knowledge to determine the quantities or operations needed.
The IALS study has yielded a wealth of analytical output of which can be downloaded
from www.ets.org/all. The key findings of this research can be summarized in
Important differences in literacy skill exist, both within and among countries.
These differences, which are much larger than those observed in studies of
school literacy such as the IEA Reading Literacy Survey (Elley, 1994) substantiate
the basic hypothesis of IALS, that is skill differences exist that are large
enough to matter both socially and economically.
Literacy is strongly associated with economic life chances and well-being.
It affects, inter alia, employment stability, the incidence of unemployment
In North America and several European countries, scores on the quantitative scale show the strongest correlation with income. There is a large ‘wage premium’ in Canada, Ireland, the United Kingdom and the United States for those whose literacy proficiency is at the highest level (level 4/5).
Literacy levels are clearly linked to occupations and industries; some occupations call for high-level skills, others intermediate skills.
The relationship between literacy proficiency and educational attainment
is complex. Although the association is strong, there are some surprising
exceptions. For example, many adults have managed to attain a relatively
high level of literacy proficiency despite a low level of education conversely,
there are some who have low literacy skills despite a high level of education.
This finding proves another of IALS hypotheses, that educational attainment
are a poor proxy for real skill. Given this fact, objective skill testing
is worth the investment.
Low skills are found not just among marginalized groups, but among significant proportions of adult populations in the countries surveyed. The data show that adult education and training programmes are less likely to reach those with low skills, who need them most.
Adults with low literacy skills do not usually consider that their lack of skills presents them with any difficulties. When asked if their reading skills were sufficient to meet everyday needs, respondents replied overwhelmingly that they were, regardless of tested skill levels. This may reflect the fact that many respondents are in jobs that do not require them to use literacy, a situation that is likely to change the knowledge society matures.
Literacy skills, like muscles, are maintained and strengthened through regular use. While schooling provides an essential foundation, the evidence suggests that only through using literacy skills in daily activities – both at home and at work – will higher levels of performance be attained.
Literacy plays an important role in the determination of wages in all countries except Poland. The contribution of literacy comes on top of the effect of education on earnings. Economists have long argued that the labour market functions as a market for skill, a market in which the demand for skill in work organizations and production processes is matched with the supply of skill offered by the labour force. Traditionally, educational attainment and experience – as measured by age or employment history – have been used as proxy measures of skill in the estimation of wage equations. The IALS data suggest that these analyses have been based on two mistaken assumptions: that data on initial educational attainment provide equivalent measures of skill across countries, and that national labour markets offer and value experience in the same way. Data show clearly the educational attainment is a poor proxy for skill, that economies differ greatly with regard to skills demanded, and that experience and skills are rewarded differently in different OECD countries.
The role literacy plays in the determination of wages is greater in economies that are more flexible and open. As measured by wage premiums, the IALS data reveal that the economic returns to literacy, when controlling for education, are largest in ‘open’ economies such as Canada and the United States. This fact has important implications for other OECD countries engaged in making their labour markets more flexible and efficient. First, steps must be taken to ensure an adequate supply of skill, given the demand of the economy. OECD countries have long relied on the educational system to provide the requisite supply of (increasingly) skilled workers. With OECD labour forces replenishing themselves at a rate of roughly 3 per cent per annum, countries can no longer rely on schools only but need to target low-skill adults, the majority of whom are currently in the labour force. Second, as part of the move towards more efficient markets for skill, policy-makers must encourage employers to demand and reward high skills while at the same time, ensuring that adequate learning opportunities are available to those economically or socially at risk because of their low skills.
Literacy outcomes vary considerably according to socio-economic status in
some, but not all, of the countries investigated. Public policy in most OECD
countries aims to reduce social disparity in economic opportunity. Economic
inequality has tended to rise over the past two decades in most countries,
despite massive investment in education. Results indicate that literacy outcomes
in some countries vary considerably by socio-economic status, with youth from
disadvantaged backgrounds performing more poorly than could be expected, given
education and experience. These disadvantaged individuals will bear large reductions
in lifetime earnings as a result. Not only is this unfair, but there is a large
cost to society as well, for example, in terms of tax revenue forgone. The
absence of disparity in some countries suggests that the problem can be addressed