Scientific Inquiry, Observation, and Experimentation
Inquiry items test the design of an experiment rather than recall of a result: why a control was needed, what was varied, and whether the conclusion follows from the data.
Variables and controls
- 独立変数 is what you change, 従属変数 is what you measure, and 制御変数 are held constant. Answers must name the controlled variables explicitly.
- 対照実験 is a comparison condition differing in one factor only. Without it, a change cannot be attributed to the factor you varied.
- Repeat and average measurements to reduce random error; describe a trend before drawing a conclusion.
Measurement
- Read to one-tenth of the smallest scale division; read a メスシリンダー at eye level at the bottom of the meniscus.
- 電流計 goes in series and 電圧計 in parallel; check the range before connecting.
- Plot 独立変数 on the x-axis; a straight line through the origin supports proportionality, but the claim must be limited to the range measured.
Reporting and safety
目的 → 方法 → 結果 → 考察 → 結論. 結果 states observations and numbers; 考察 explains them. Wear 保護眼鏡, ventilate when heating, and never point a test tube at anyone.
Worked example. A student hangs 0, 20, 40 and 60 g on a spring and measures extension, using the same spring, the same ruler position and three repeats per load. Plotting extension against mass gives a straight line through the origin, so within 0–60 g the extension is proportional to the load. Extending that claim to 500 g would be unsupported, because no data were taken there.
Traps. Writing a conclusion where a result belongs; changing two variables at once; omitting repeats; drawing a curve through points that clearly lie on a straight line; leaving the control condition out of the design.