The GED® Science Test focuses on the fundamentals of science reasoning, striking a balance of deeper conceptual understanding, procedural skill and fluency, and the ability to apply these fundamentals in realistic situations. In order to stay true to this intention, each item on the Science Test is aligned to one science practice and one content topic.
The science practices can be described as skills that are key to scientific reasoning in both textual and quantitative contexts. The science practices are derived from important skills enumerated in the Career and College Ready Standards as well as in The National Research Council’s Framework for K-12 Science Education.
The Science Test also focuses on three major content domains:
- Life science
- Physical science
- Earth and space science
The science content topics, which are drawn from these three domains, provide context for measuring a test-taker’s abilities to apply the reasoning skills described in the practices. The content topics focus on science that reflects both that which is taught in many high school-level science courses and that which is most relevant and useful for an adult population. To measure this content at a range of levels of complexity, several different item types are used in the test, including multiple choice, short answer, drag-and-drop, hot spot, and fill-in-the-blank.
Given these priorities, the GED® Science Test adheres to the following parameters:
- Approximately 40 percent of the test focuses on life science, roughly 40 percent focuses on physical science, and approximately 20 percent focuses on Earth and space science.
- The test includes items that test textual analysis and understanding, data representation and inference skills, as well as problem solving with science content.
- Each item on the Science Test is aligned to both one science practice and one content topic.
- Each item is also aligned to one Depth of Knowledge level of cognitive complexity, based on the appropriate alignment to a science practice.
- Approximately 80 percent of the items are written to a Depth of Knowledge level of 2 or higher.
- The contexts within which problem solving skills are measured were taken from both academic and workforce contexts.
- Approximately 50 percent of the items are presented in item scenarios, in which a single stimulus (which may be textual, graphic or a combination of both) serves to inform two to three items. The rest of the items are discrete.
The science content topics describe key concepts that are widely taught in a variety of high school-level courses and are relevant to the lives of GED® test-takers. The content topics are designed to provide context for measuring the skills defined in the science practices.
The science practices maintain a close relationship with the science content topics. More specifically, the primary focus of the GED® Science Test continues to be the measurement of essential reasoning skills applied in a scientific context. However, test-takers should still be broadly and generally familiar with each of the basic concepts enumerated in the science content topics and subtopics, and they should be able to recognize and understand, in context, each of the terms listed there. Nevertheless, test-takers are not expected to have an in-depth and comprehensive knowledge of each subtopic. Rather, the stimuli about which each question pertains provides necessary details about scientific figures, formulas, and other key principles. For example, a question may include answer options and stimuli that contain specific terms drawn from the content subtopics; however, test-takers are never asked to formulate their own definition of a term without the item providing sufficient contextual support for such a task.
These themes have been selected to ensure that the testcovers a wide range of important scientific topics, but they are also intended to function like a lens by drawing focus to a distinct subset of ideas within each content topic. That is, items from any of the three content domains of life science, physical science, and Earth and space science can pertain to one of these two themes, but content that falls outside the spheres of these themes do not appear on the GED® Science Test.
- Human Health and Living Systems, the first focusing theme, pertains to material that is vital for the health and safety of all living things on the planet. Topics explored in this area of focus include the physical body and characteristics of humans and other living things. System of living organisms and related topics (e.g. diseases, evolution, and heredity) are also covered. This crosscutting concept also examines the mechanisms for how the human body works on chemical and physical levels. Within the domain of Earth and space science, topics are focused on how the environment affects living things and human society, as well as on how humans and other organisms affect the environment.
- Energy and Related Systems, the second focusing theme, deals with a fundamental part of the universe. Topics in this area of focus cover sources of energy, transformations of energy, and uses of energy. Within the domain of life science, this theme is reflected in content exploring how energy flows through organisms and ecosystems. Similarly, the Earth’s geochemical systems are touched upon in Earth and space science. Topics related to how humans gain energy in their bodies and the results of the use of that energy are also relevant to this theme.