During reading groups, a third-grade teacher notices that a number of students have difficulty understanding the words evolution and biodiversity found in a life science text. Which of the following strategies is most likely to support the students in their ability to make meaning out of these complex content-specific vocabulary words?

• A. Asking the students to use prior knowledge of the topic they are learning about to determine the words' meanings
• B. Providing instruction to the students on how to use dictionaries and online sources to look up the words' definitions
• C. Having the students do a think-pair-share in which they discuss possible definitions for the words using context clues
• D. Conducting a mini-lesson with the students on ways to use their knowledge of roots and affixes to construct meaning

Answer: (D)

Decoding word parts is a powerful way to unlock complex science terms. When students learn to identify roots and affixes, they gain a practical toolkit to construct meaning for unfamiliar words like evolution and biodiversity. For example, recognizing bio- as life, divers- as varied, and the -ity suffix as a state or quality helps students see that biodiversity refers to the variety of life, while understanding that -tion marks a process helps interpret evolution as a process of development. A brief mini-lesson that explicitly teaches how to use these parts gives students a reusable strategy they can apply across many science terms, making comprehension more independent and efficient as they read.

While other strategies can support understanding, they don’t provide this durable decoding tool as directly. Relying on prior knowledge may be limited when terms are unfamiliar; looking up definitions can slow reading and may not help students grasp how the word is built; using context clues without a clear rule can lead to guesses that aren’t reliable. The morphology-focused approach gives students a concrete, transferable method to derive meaning from new vocabulary in science texts.