Recent years have witnessed a significant increase in the interest in international assessments of student performance. In such assessments it is mandatory that all the different-language texts be equivalent to each other, that is, equally difficult to understand. The article summarizes a study made on the topic, examining the problems of equivalence encountered when translating texts in international reading literacy assessments. In the study, three English and Finnish texts used in the PISA 2000 reading test were compared text-analytically. The analysis revealed six different types of problem, which, moreover, differed considerably between the three texts. As a result of the problems, none of the three text pairs were fully equivalent in difficulty. The study suggests that it will probably never be possible to attain full equivalence of difficulty in international reading literacy studies; however, by developing the translation work, a relatively high level of equivalence (and validity) seems attainable.

In international achievement studies, a common test is typically used which is translated into the languages of the participating countries. For the test to be valid, all the translations and different-language test versions need to be equally difficult to read and answer. An underestimated and underdiscussed threat to this validity is unwanted literal translation. This paper discusses the problem of unwanted literal translation in international achievement studies. It defines what is meant by unwanted literal translation and explains why it is a threat to the validity of international achievement studies and why it is so difficult to avoid. It also discusses problems there have been when translating these tests which may have promoted unwanted literal translation and provides suggestions on how to improve the translation practices so as to ensure that the translations are in as natural and idiomatic language as possible.

The article reviews research and findings on problems and issues faced when translating international academic achievement tests. The purpose is to draw attention to the problems, to help to develop the procedures followed when translating the tests, and to provide suggestions for further research. The problems concentrate on the following: the unique and demanding purpose of the translation task, the partly contradictory task specifications and translation instructions, the indecision as to whether to produce one or two target versions, the indecision as to whether to use one or two source versions, inadequate revision and verification, deficient translator competences, and a lack of time. To solve the problems, the article suggests the following: ensuring that the translation guidelines provide a right, unequivocal, and balanced picture of the purpose of the translation task; ensuring the equivalence of the two source versions; putting more emphasis on revision, and ensuring that the verification is sufficiently thorough; using only qualified translators, providing them with training in test translation, and including also subject matter and testing specialists in the translation teams; and allotting sufficient time to the translation work. However, the main lesson from the review is that more research in the field is badly needed.