EF English Proficiency Index

The EF English Proficiency Index (EF EPI) is a report which attempts to rank countries by the average level of English language skills amongst adults. It is "not a statistically controlled study", as The Economist states; "the subjects took a free test online and of their own accord. They were by definition connected to the internet and interested in testing their English; they will also be younger and more urban than the population at large."

It is the product of EF Education First, a global language training company, and draws its conclusions from data collected via English tests available for free over the internet. The report was published for the first time in March, 2011 based on the results of over 2 million test takers. The most recent, sixth edition was released in November, 2016.

The EF EPI sixth edition was calculated using test data from 950,000 test takers in 2015. The test takers were self-selected and no demographic information was collected on them. The tests are used by the company for marketing and placement purposes. 69 countries and 3 territories appear in the sixth edition of the index. In order to be included a country was required to have at least 400 test takers total.

The report is composed of a country ranking table, several pages of analysis with graphs correlating other economic and social factors with English proficiency, and analysis of each region or continent. The 2016 report and accompanying country fact sheets include English proficiency levels by gender, age group, and region, within countries, and some English proficiency scores by city. The website displays portions of the report and has analysis of English skills in many countries and territories.

The EF English Proficiency Index has been criticized for its lack of representative sampling in each country. The report states that participants in the tests are self-selected and must have access to the internet. This pushes the index towards the realm of an online survey rather than a statistically valid evaluation.

However, there are few alternative comparisons available of countries by their English skills, and those that exist are smaller in scale, as is the case with a reported British Council study, or they have other sampling flaws, as is the case with rankings of countries by standardized English test scores such as the TOEFL. The European Commission performed a language survey, SurveyLang, which tests a representative sample of 15-year-old European students on their foreign language skills. The first report and data sets were released for 13 European countries in June 2012.

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