In Connected Knowledge and the language barrier Apostolos Koutropoulos mentions the problem of languages as a barrier in understanding knowledge.
I would like to mention another barrier behind this language barrier. It is the cultural barrier. A blogpost in a non English language often comes from members from other cultures with different views.
Students only reading English language posts do miss a lot of the ‘weak ties’ and challenging information from foreign people. They miss the fine differences and nuances of cultural richness and cultural differences.
Culture (1) is: An integrated pattern of human knowledge, belief, and behavior that depends upon the capacity for symbolic thought and social learning.
Culture (2) is: The set of shared attitudes, values, goals, and practices that characterizes an institution, organization or group.
Both kinds of culture as mentioned above are different in different groups and countries.
Even education and science in non-English countries differs from that in English countries. The education system and the content of education differs.
In Anglo-Saxon education various forms of creative and critical writing is important in English lessons. In the Netherlands the lessons in Dutch Language are different with less writing and more time for learning to understand language. The goals are different.
In USA far more people seem to believe constructivistic philosophical views on epistemology than in continental Europe.
It is not only a language barrier, it is a very high and almost invisible cultural barrier.
The cultural barrier often is invisible because of the language barrier.