Each unit focuses on a small, powerful set of unit vocabulary words that fall within two categories. The first category, science content vocabulary, are words that are essential to understanding and talking about a particular science topic. For example, in the grade 5 unit Patterns of Earth and Sky, some unit vocabulary words are gravity, orbit, solar system, and star. The second category, science practice vocabulary, are those words that are used across different domains of science. These words, such as claim, data and model, which are used across the program. Students learn both categories of words through immersion (they are continually exposed to the words in oral and written language, including books, words, and key concepts posted on the classroom wall), explicit instruction (words are defined, discussed, and highlighted within individual lessons), and repeated practice (students use vocabulary supports for discussions and writing and have many opportunities to use new words in meaningful contexts).

The ultimate goal is for students to gain active control over academic science vocabulary — that is, being able to read, write, and speak using words such as molecule, environment, evidence, and data fluently and accurately, and to have a deep and nuanced understanding of what these words mean, beyond simply defining them. In addition, as mentioned, all units are written to include academic words that are common across academic settings and disciplines. This means that students not only have experiences with science and engineering vocabulary, but they also see, hear, and use vocabulary that they will likely encounter in other academic settings during their schooling. Unit vocabulary and academic language are incorporated into the units in the following ways:

• Units target a small but powerful set of science content and process words. The program emphasizes strategic use of a few key words essential for understanding and talking about the topic of study and engaging in the work of science.
• Strategic focus on the unit’s content vocabulary words:
  • Students have multiple opportunities to use unit vocabulary words. In each unit, students have many encounters with unit vocabulary in multiple modalities (doing, talking, reading, writing, visualizing).
  • Teachers provide explicit instruction and practice. Each unit vocabulary word is introduced, defined, discussed, posted on the classroom wall, and incorporated into many oral and written activities throughout the unit. Throughout the grades, various vocabulary routines are used to help students gain practice using new science words.
  • Learning activities support productive as well as receptive language. Not only do students hear and read the words, but they are encouraged, prompted, and reminded to use them in their discussions and written work. This is done in a variety of ways, including through teacher modeling, words posted on the classroom wall and on charts, sentence frames and graphic organizers, and class discussion.
  • Emphasize use of vocabulary in varied contexts. By the end of a unit, students should be able to use their own words to explain unit vocabulary, be able to use vocabulary words correctly in a variety of contexts, understand their relationships to other words, and effortlessly use them in their speech and writing when they need to explain an idea.
  • Highlight and support use of scientific academic language. At strategic points throughout the program, the teacher guides students in thinking about how scientific language differs from everyday language or from language used in other school subjects, and helps students see the power of using scientific language to explain science ideas.

The following three tables provide exemplar word lists for kindergarten and grade 1, grades 2–5, and grades 6–8, respectively. Each table includes the targeted vocabulary from one unit at each grade level, along with a representative set of science and engineering vocabulary and other common academic vocabulary that appears across the grade band.

Kindergarten	Grade 1
Pushes and Pulls unit words: object direction distance force exert engineer visualize solution design	Spinning Earth unit words: day daytime Earth horizon nighttime data organize pattern predict record
Commonly used scientific, engineering, and other academic vocabulary: answer, away, because, block, cause, change, communicate, compare, create, data, describe, diagram, different, direction, discuss, effect, evidence, exert, explain, explanation, explore, goal, horizon, human, information, investigate, left (direction), living thing, material, model, movement, near, object, offspring, observe, organize, predator, predict, problem, project, pull, push, represent, revise, right (direction), same, science, scientists, shade, similar, solve, solution, source, still, strength, structure, strong, survive, test, tool, toward, visualize, world Bolded words are directly taught in at least one unit in kindergarten and first grade.

Grade 2	Grade 3	Grade 4	Grade 5
Changing Landforms unit words: geologist landform evidence observation stable visualize explanation model diagram erosion scale	Inheritance and Traits unit words: investigate organism trait pattern observe species variation data explanation offspring genes inherit reproduce environment	Energy Conversions unit words: engineer function synthesize system electrical device energy electrical energy form (of energy) argument claim evidence converter convert criteria source design electrical grid transfer	Ecosystem Restoration unit words: ecologist observe matter molecule synthesize model argument claim evidence environment ecosystem food web organism data restoration energy decomposer soil nutrient
Commonly used scientific, engineering, and other academic vocabulary: analyze, argument, change, claim, communicate, compare, conclude/conclusion, conduct, connect, criteria, data, depend, describe, design, develop, diagram, different, discover, effect, evaluate, evidence, explanation, explore, function, growth, human, infer/inference, information, investigate, material, measure, model, natural, need, observe/observation, organize, pattern, predict, problem, process, purpose, question, record, represent, results, sample, scale, scientific argument, similar, solve/solution, source, structure, study, synthesize, system, test, variable, visualize Bolded words are directly taught in at least one unit in grades 2–5.

Grade 6	Grade 7	Grade 8
Unit Words: Weather Patterns weather condensation evaporation air parcel energy temperature water vapor transfer cloud troposphere wind	Unit Words: Populations and Resources ecosystem population reproduction energy energy storage molecule consumer population resource population indirect effect competition	Unit Words: Force and Motion collision exert force friction mass velocity
Commonly used scientific, engineering, and other academic vocabulary: analyze, apply, average, cause, change, claim, connect, constraint, control, criteria, cross-section, data, deliverable, demonstrate, describe, design, develop, diagram, dossier, effect, evaluate, evidence, examine, experiment, explanation, explain, factor, female, fluctuation, function, histogram, identify, infer, input, intern, interpret, investigate, isolate, iterative testing, locate, male, model, observe, optimal, pattern, predict, process, proposal, reasoning, record, refute, relevant, review, revise, role, sample, scale, science, scientific argument, scientific communication, scientific community, source, stability, summarize, system, test, trade-off, trend, variable, visualize Bolded words are directly taught in at least one unit in grades 6–8.

Earth	Life	Physical
Unit Words: Weather Patterns weather condensation evaporation air parcel energy temperature water vapor transfer cloud troposphere wind	Unit Words: Populations and Resources ecosystem population reproduction energy energy storage molecule consumer population resource population indirect effect competition	Unit Words: Force and Motion collision exert force friction mass velocity
Commonly used scientific, engineering, and other academic vocabulary: analyze, apply, average, cause, change, claim, connect, constraint, control, criteria, cross-section, data, deliverable, demonstrate, describe, design, develop, diagram, dossier, effect, evaluate, evidence, examine, experiment, explanation, explain, factor, female, fluctuation, function, histogram, identify, infer, input, intern, interpret, investigate, isolate, iterative testing, locate, male, model, observe, optimal, pattern, predict, process, proposal, reasoning, record, refute, relevant, review, revise, role, sample, scale, science, scientific argument, scientific communication, scientific community, source, stability, summarize, system, test, trade-off, trend, variable, visualize Bolded words are directly taught in at least one unit in grades 6–8.