Every good investigation starts not with an experiment, but with a question. Exploring is the creative first stage of scientific inquiry — where you act like a real scientist, turning idle curiosity into a focused, testable idea. It’s also where a lot of Internal Assessment marks are won or lost: a sharp research question and a properly justified hypothesis set up everything that follows. Get the exploring right and the rest of the investigation almost designs itself.
📘 What you need to know
Exploring means using curiosity and existing knowledge to formulate a focused research question and a testable hypothesis
A strong investigation studies one independent variable against one dependent variable, in depth
You must consult a variety of sources to understand the scientific context before finalising your question
A research question (RQ) is focused, specific, and clearly links the independent and dependent variables
A hypothesis is not a guess — it’s a testable prediction with a scientific justification, best written as “If…, then…, because…”
The “because” must rest on established physics (a law, a principle, or a formula)
What exploring actually involves
Exploring is the imaginative part of the process. It draws on your natural curiosity and the physics you already know to produce a focused research question and a testable hypothesis. Crucially, it takes independent thinking: you consult a range of sources to understand the science behind your idea, then make a clear, justified prediction about what will happen.
Exploring moves from a broad idea to a sharp, justified hypothesis — each step narrows and strengthens the last.
Showing insight and independent thinking
The best investigations often begin with a simple question about a standard experiment — something like “measuring the acceleration due to gravity, g.” You show insight by reframing it as a comparative enquiry: instead of just measuring, you ask to what extent one factor affects another. That signals you’re thinking about the assumptions baked into a physical model.
The single most common mistake I see is trying to investigate too many variables at once. A question like “How do the length and mass of a pendulum affect its period?” is really two investigations bolted together. Pick one factor and explore it thoroughly — depth beats breadth every time in the IA.
Consulting a variety of sources
Before you can write a high-quality question, you need background information — this is a crucial research step, not an optional extra. Good research helps you understand the underlying physical principle, find established scientific values to compare against, and identify a suitable method for collecting data.
📚 Where to look
Your class notes — the quickest route to the core principle
Your textbook — for defining equations and derivations
The IB data booklet — for accepted constants and relationships
Reliable databases (e.g. NIST, CRC Handbook) — for accepted material values
Trusted simulations (e.g. PhET) — to explore behaviour before building anything
This research gives your investigation its scientific context — it shows the assessor you understand the physics behind your question, rather than experimenting blindly.
Formulating the research question
A research question must be focused, specific, and must clearly state the link between the independent and dependent variables. “How does gravity affect objects?” is far too general to investigate. A good RQ usually takes the shape “What is the relationship between x and y?”
The shape of a good RQ
“What is the relationship between x and y?”
For example: “What is the relationship between the length of a simple pendulum and its period of oscillation?” — one independent variable (length), one dependent variable (period), and a clear link between them.
Writing a justified hypothesis
A hypothesis is not a guess. It’s a clear, testable statement that predicts the outcome and explains it using established physics. The cleanest structure is “If…, then…, because…” — the “if” and “then” give the prediction, and the “because” supplies the scientific justification.
If… change the IV
→
then… predict the DV
→
because… the physics
The “because” is where the marks are. A statement like “If the length increases, the period will increase” is only a prediction. It becomes a scientific hypothesis when you add the justification — for instance, that the pendulum equation shows the period is proportional to the square root of the length.
Period of a simple pendulumT = 2π√(L ÷ g)
Quick recap: explore with curiosity, then narrow to one IV and one DV; consult varied sources for context; write a focused RQ (“relationship between x and y“); and justify your prediction with an “If…, then…, because…” hypothesis grounded in real physics.
EXAMPLE 1
Exploring an oscillation investigation
Broad idea
I’m interested in the factors that affect the time it takes for a pendulum to swing.
Consulting sources & gaining insight
My textbook gives the period of a simple pendulum as T = 2π√(L ÷ g).
This shows the period depends on the length L and the free-fall acceleration g.
Crucially, the mass m of the bob doesn’t appear — suggesting the period is independent of mass.
Research question
“What is the effect of the length of a simple pendulum on its period of oscillation?”
Hypothesis
If the length of the pendulum is increased…then the period of oscillation will also increase…because the formula T = 2π√(L ÷ g) shows the period is proportional to the square root of the length.
EXAMPLE 2
Exploring an electrical resistance investigation
Broad idea
I want to investigate the factors that affect the electrical resistance of a wire.
Consulting sources & gaining insight
My textbook defines resistivity through ρ = RA ÷ L, where R is resistance, L is length and A is cross-sectional area.
The formula shows resistance is directly related to length and inversely related to cross-sectional area.
Resistivity ρ is a property of the material, so accepted values can be found in a reliable source such as the CRC Handbook.
Research question
“What is the relationship between the length of a constantan wire of constant cross-sectional area and its electrical resistance?”
Hypothesis
If the length of the constantan wire is increased…then its resistance will increase proportionally…because the formula R = ρL ÷ A states that resistance is directly proportional to length, for a constant cross-sectional area and temperature.
💡 Top tips
Start from a standard experiment and add a twist — a comparative “to what extent…” framing shows insight
One IV, one DV. If your question contains an “and”, it’s probably two investigations
Let the “because” carry real physics — name the law, principle, or equation behind your prediction
Check feasibility early: a brilliant idea is worthless if you can’t run it with school equipment in the time available
⚠ Common mistakes
Writing an RQ that’s too general (“How does gravity affect objects?”) instead of naming the two variables
Handing in a prediction with no justification — that’s not a hypothesis, it’s a guess
Trying to investigate several variables at once, so nothing gets explored in depth
Being afraid to refine the RQ — adjusting it after early research is part of the scientific process, not a failure
Up next: Designing in Physics — once your research question is sharp, we turn it into a practical, step-by-step methodology: identifying and justifying variables, choosing a sensible range and number of measurements, and writing a procedure another physicist could replicate exactly.
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