Science: Core Ideas, Investigation Design, and Student Misconceptions
What the Science CKT tests
The science section assesses core ideas in life, physical, and Earth/space science, engineering design, and the practices of investigation and explanation. Items often present a classroom scenario, a student's claim, or a simple data table and ask what the teacher should do next.
Core rules
- Three-dimensional instruction combines disciplinary core ideas, science and engineering practices (planning investigations, analyzing data, arguing from evidence, modeling), and crosscutting concepts (cause and effect, patterns, systems, energy and matter).
- A fair test changes one independent variable and holds others constant. Repeated trials and careful measurement reduce error.
- Models are explanatory tools with limits, not decorations. Observations are what you measure or see; inferences are interpretations.
- Misconceptions are coherent, so they need discrepant evidence and explanation, not just correction.
Worked example
Groups plant beans to test light. Group A gives one plant 8 hours of light and 50 mL water; Group B gives another plant 2 hours of light and 100 mL water. Group B's plant grows taller. Reasoning: light and water both differ, so the growth cannot be attributed to light. The design confounds variables. Revision: keep water at 50 mL for both, vary only light duration, use several plants per condition, and measure height at the same times. Then a claim about light is supported.
Traps
- Teaching the scientific method as a fixed five-step sequence.
- Treating a hands-on demonstration as inquiry when students only watch.
- Confusing mass and weight, or weather and climate.
- Accepting the plant got food from soil; plants make sugar via photosynthesis, while soil supplies water and minerals.
- Using vocabulary as the goal rather than as a label for investigated phenomena.