Since integration concerns complicated phenomena and refers to a very widespread
field, one cannot restrict the evaluation of a progress (or non-progress) in integration
to one single unit of measurement. There is no such thing as "one meter of
integration" or "two kilos of integration" which would make comparisons over time
and/or between two countries an easy task.
As a way out, one can only try to identify facts and phenomena giving an impression
of the current social, economic, cultural and political role migrants play in a given
society as well as at changes occurring over time. These indicators of integration can
be selected from all four dimensions of integration. But in addition to this the host
society - as was already mentioned - is very important as well, because public
opinion - though only measurable with a good deal of doubt left behind - can for
example give a hint as to the willingness to accept immigrants.
Sometimes, violent attacks on foreigners are taken as an indicator of integration. To