Sentence-starters for rich explanations
Writing out a full, gapless explanation is something that students need scaffolding for. Students are often unfamiliar with using the types of language that express comparisons between ideas or that states a position based on evidence.
In a unit on natural selection for example, students might be given a big question they have to answer that requires a rich and multifaceted causal explanation. One teacher used the question: “If we think about the increasing length of giraffe’s necks, why does this trait in the population change, when over time the available food for these giraffes is located higher and higher in the trees?” To aid in the process of developing a full causal explanation, the teacher gave students a set of conceptual terms and phrases that had been explored throughout the unit. These included “variability”, “random mutations”, “offspring”, “environmental changes”, “adaptations”, “physical traits” etc.
[Click here to hear how Jake used this strategy with high school school students in a unit on natural selection].
Students were also given sentence-starters. Some of these included: “At first the giraffe population will..”, “The long-necked giraffes will…”, “If leaves are higher off the ground then…”, “Giraffes that could be able to reproduce are…”
Click image to enlargeSuch scaffolding is helpful to all students who may typically only write a sentence or two and consider that a full explanation. It is particularly helpful to English Language Learners, who are still trying to figure out the use of scientific language in addition to conversational language.
Constructing these explanations is typically done in small groups, and to allow everyone participate, it is helpful to give each person in the group a cognitive role (as opposed to a role like “materials manager”, which requires no intellectual work). Examples of these roles are “the clarifier” who reads the current explanation with an eye for sentences that are ambiguous and need re-writing, “the synthesizer” who seeks to make logical connections between different parts of the explanation, and “the task manager” who checks that the developing product of the group meets the requirements of the task that the teacher has outlined.
Although this is done in small groups, these explanations can each be presented in a whole group setting. In this whole group setting, the final explanations might be compared to an initial consensus model that the students and teacher had developed earlier in the unit. Students may revise their group explanation (but now done as individuals) based on the whole class sharing and critiquing of group models/explanations.
