Research question(s). How does scaffolding instruction of biology concepts through constructing definitions and analogies influence students' understanding? (1) How do students approach the process of constructing analogies for different science concepts? (2) How does student engagement vary during in-class analogy construction and definition activities?

Context. This intervention took place in a ninth grade high school biology class. Of the 29 students involved in the study, 10 were English Learners (EL) or Reclassified Fluent English Proficient (RFEP), mainly Spanish-speaking students. The study explored the use and construction of definitions and analogies to improve vocabulary development and comprehension of biological concepts. Vocabulary became a focus, because of students' low performance in vocabulary exams and chapter assessments, especially among ELs.

Methods and data. Data were collected in two phases within a four-week span. In the first phase for baseline data, the students were asked to match the definition to the appropriate vocabulary word. During Phase I students defined and wrote flashcards for each of the targeted vocabulary words (N=12). Prior to the test they had a chance to study the flashcards independently. During the second phase, the students were given a new set of concept words (N=13) and asked to define and construct analogies for each. The students were then given a test similar to the first.

Results. Whole class scores increased from a baseline of 40% to 54% at the end of Phase I and decreased to 53% at the end of Phase II. The EL subgroup increased from a baseline of 33% to 55% at the end of Phase I and decreased to 52% at the end of Phase II. The Non-EL subgroup, increased from a baseline of 43% to 53% at the end of Phase I, and remained at 53% at the end of Phase II. There were notable increases in median scores within each subgroup. Whole class scores increased from 31% to 58% at the end of Phase I and decreased to 53% at the end of Phase II. However, the EL subgroup increased from a baseline of 25% to 58% at the end of Phase I and increased to 62% at the end of Phase II. The Non-EL subgroup increased from 37% to 66% at the end of Phase I and decreased to 53% at the end of Phase II. The median score increase from baseline to the end of Phase II was greater for the EL group: 37%, compared to 16% for to the Non-EL subgroup. These increases suggest that explicit instruction on vocabulary influences comprehension of concepts. The effectiveness of student-generated analogies varied depending on the complexity of the concept and the quality of the analogy.

Grade level. High School 9-12

Data collection methods. Vocabulary assessment, Analogy Vocabulary Sheets, Student engagement observations, Parent survey.

Curriculum areas. Biology, Science

Instructional approaches. Vocabulary Definitions, Analogies, Flashcards, Partner/Independent Study Group