analyzed has been continually expanded. From 1999 until 2004, the ranking was issued with the German magazine Stern. Since 2005 it has been published by the German weekly newspaper Die Zeit. Methodology In contrast to other university rankings, the CHE University Ranking incorporates more aspects of teaching rather than research. To evaluate teaching, it uses surveys of undergraduate and graduate students and professors. To evaluate research, it uses faculty surveys, bibliometric analysis, survey of university administrators and analysis of other data sources. Reception The CHE University Ranking has faced criticism for neither publishing the data set itself, nor a detailed scientific description of its methodology. In particular, critics have pointed out several weaknesses in the CHE ranking: The criterion "recommendation of professors for a course of study" has only little significance, since it is doubtful whether external professors can actually express a qualified opinion on studying at another university. Research award winners are not taken into account at all in the research ranking. For reasons of information privacy, survey documents are distributed by the colleges or universities, rather than by CHE directly. This may allow for arbitrary manipulation by the colleges or universities. Ranking parameters and samples are set arbitrarily. For example, it is criticized that the samples are often too small to provide meaningful results. Multiple responses are not standardized, e.g. in the area of research strength by professors. This makes the results incomparable for the reader and leads to confusion, since a relative comparison is no longer possible - even though results are given in percentages. In some cases, there are considerable data gaps in the CHE ranking (e.g. number of graduates or average grade), so that the universities are not comparable. In 2007, Switzerland and Austria withdrew from the CHE University Ranking, citing significant data and methodological deficiencies. Some university departments, most notably in the fields of sociology, history, and media studies, have boycotted the ranking, leading to some subjects completely being excluded. In contrast, the Educational Policy Institute has called the CHE ranking as "nothing less than brilliant" in a comparison of 19 international university rankings. Unlike "rankings with often questionable indicators", the German ranking actively involves the universities in its compilation and thus achieves a "high data quality at the institute level." In 2005, the European University Association claimed that "the system used by CHE to evaluate universities is probably the best model available in