Unit 01 · Required Investigation
Paper Helicopter: Design, Drop & Measure
Create a complete scientific record of how rotor length relates to fall time under controlled conditions. Preserve the plan, raw observations, deviations, calculations, graph decisions, uncertainty, and final evidence-based explanation so another investigator can audit what you did.
Use scissors only for normal paper cutting. Work from stable floor-level footing in a clear drop area. Never climb on furniture, stairs, railings, counters, or other structures to increase drop height. Keep people, pets, fans, open windows, traffic paths, liquids, heat, electrical equipment, and fragile objects clear. Stop if airflow, interruptions, damaged equipment, unsafe footing, or environmental changes prevent the approved procedure from being performed safely and comparably.
A. Preregistered question and prediction
Core question: How does rotor length affect the mean fall time of a paper helicopter released from a fixed height under the same stated conditions?
If rotor length increases, then mean fall time will __________ within the tested range because __________. A result that would fail to support this prediction is __________.
Do not rewrite a prediction after seeing the results and present the revision as though it came first. If your thinking changes, date and document the change.
B. Variables, operational definitions & controls
| Independent variable | Rotor length (cm). Planned levels: ______________________________ |
|---|---|
| Dependent variable | Fall time (s), from __________________ to __________________ according to the same timing rule for every trial. |
| Drop height | __________ cm, measured from __________________ to __________________. |
| Controls | Paper source/type, body dimensions, rotor width, folds, mass/paper clips, drop height, release method, location, timing method, landing surface, and other documented conditions. |
| Likely confounders | ____________________________________________________________ |
| Minimum design | At least three rotor lengths and five recorded trials per length. |
C. Measurement-quality statement
| Length instrument / resolution | ________________________________________ |
|---|---|
| Timing instrument / resolution | ________________________________________ |
| Pre-use/reference check | ________________________________________ |
| Likely random variation | ________________________________________ |
| Possible systematic bias | ________________________________________ |
D. Approved protocol
- Construct helicopters identical in all planned controlled features except rotor length.
- Measure, label, and record each rotor length before testing.
- Measure the fixed drop height using the documented reference points.
- Verify the test area satisfies the safety conditions and note material environmental conditions.
- Run conditions in the planned order: ________________________________________.
- Release using the operationally defined technique without adding an unplanned push or spin.
- Measure fall time using the same start/stop rule.
- Record each raw trial immediately with its unit and relevant observation notes.
- Complete at least five trials for every condition. Do not selectively repeat trials because of the result.
- Document protocol deviations, interruptions, damaged designs, or environmental changes before deciding how they affect analysis.
Could another learner perform the investigation from this record without additional verbal instructions? If not, revise the protocol before Trial 1.
E. Raw-data record
Enter raw observations first. Do not replace raw trials with calculated summaries.
| Rotor length (cm) | Trial 1 (s) | Trial 2 (s) | Trial 3 (s) | Trial 4 (s) | Trial 5 (s) | Additional trial(s) | Notes / deviations |
|---|---|---|---|---|---|---|---|
F. Analysis table
| Rotor length (cm) | n analyzed | Mean fall time (s) | Minimum (s) | Maximum (s) | Range (s) | Exclusion/analysis note | |
|---|---|---|---|---|---|---|---|
Use the Khaemenes Scientific Calculator to verify arithmetic when permitted. Keep every summary traceable to the raw table.
G. Graph record
Create a graph with rotor length (cm) on the x-axis and mean fall time (s) on the y-axis. Include a descriptive title, units, readable intervals, and an axis range that does not conceal or exaggerate the numerical pattern.
Graph type: __________. Axis-range decision: __________. Points connected/trend representation? __________. Why is that choice justified by what was actually measured?
Dataset Lab may be used to verify or compare a visualization, but the student remains responsible for scale, encoding, and interpretation.
H. Anomaly & deviation decisions
For each flagged observation, document what was unusual, whether a recorded event explains it, whether it remains in the primary analysis, and whether the conclusion changes materially under another defensible treatment.
| Trial / condition | What was unusual? | Documented cause? | Analysis decision | Effect on conclusion |
|---|---|---|---|---|
I. Result → interpretation → limitation
- Result: Describe the numerical pattern using actual values, tested range, and variation.
- Interpretation: Explain what the pattern suggests about rotor length under these controlled conditions.
- Alternative explanation: Identify the strongest plausible remaining alternative/confounder.
- Limitation: Name the mechanism—not merely “human error.”
- Improvement: Propose one specific change and explain which limitation it addresses.
- Scope: State one population/design/condition beyond which these results should not automatically be generalized.
J. CER conclusion
Answer the investigation question at a scope justified by the tested designs.
Use relevant numerical results and variation. Do not cherry-pick only the most favorable trial.
Connect the evidence to the investigation design and a cautiously stated scientific mechanism; address uncertainty or an important alternative explanation.
K. Mentor evidence-defense conference
Bring the preregistered plan, raw table, graph, calculations, deviation record, and CER to the Science Mentor. Be prepared to defend:
- why the comparison was fair enough to interpret;
- which result came directly from measurement rather than expectation;
- why any exclusion was scientifically justified;
- what the graph reveals and conceals;
- what evidence would make you revise the conclusion.
Mentor and Science Studio support checking and revision; they do not replace the student's observations or independent mastery evidence.
L. Evidence-complete gate
Before selecting “Record Evidence Complete,” verify that the record contains the preregistered prediction, operational definitions, measurement statement, protocol, raw observations, deviations, calculations, graph, anomaly decisions, result/interpretation/limitation analysis, and CER.