Popular science articles should be accessible to general readers.
Tips
usage
Positive — praises clear, plain language. Typical subjects: 语言, 文章, 讲解, 说明. Compare with 深入浅出, which adds that the content is deep; 通俗易懂 just says it's accessible.
memory
Two adjective pairs: 通俗 (common + customary = colloquial/popular) + 易懂 (easy + to understand). Both halves reinforce plainness.