In a study published in Critical Inquiry in Language Studies scientists at the University of Puerto Rico in Mayagüez looked at bilingual literacy in Puerto Rico, a country where instruction is predominantly in Spanish and science teaching at the college level often involves the use of both English and Spanish. The authors found professors used three main strategies: using mostly Spanish and English when referring to technical terms; using bilingual teaching materials and diagrams; and assigning English-language readings but discussed them in Spanish.