ISTANBUL — Baris Dede, a game design student, had a question: How easily did Viking longboats glide through the water? Dilara Diner, a psychologist, wanted to double-check a symptom of hysteria.

But these Turks were not able to quickly find out what they wanted. Since late April the Turkish government has blocked one of the world’s go-to sources of online information, Wikipedia.

After Wikipedia refused to remove unflattering references to Turkey’s relationship with Syrian militants and state-sponsored terrorists, officials simply banned the whole site.

Several weeks into the ban, some Turks are still struggling to remove Wikipedia searches from their muscle memory.