Good scientific investigations start with a genuinely investigable question — one specific and testable enough to actually gather data on, rather than a vague or unanswerable one ("Does more sunlight help plants grow taller?" versus "Is nature good?"). From a question, you form a hypothesis: a reasoned, testable prediction based on existing knowledge, usually structured as "if... then..." — not a random guess, but an educated one you can genuinely test and potentially prove wrong. Spotting patterns in prior observations, or noticing something unexpected, is often what sparks a good investigable question in the first place.
Example
Noticing that plants near a window seem to grow taller than those in a dim corner might lead to the investigable question "does more sunlight increase plant height?" and the hypothesis "if a plant receives more sunlight, then it will grow taller, because sunlight is needed for photosynthesis and energy production."
Key terms
Investigable question:
A specific, testable question that can be answered by gathering data.
Hypothesis:
A reasoned, testable prediction, often structured as "if... then..."
Questions
1. An investigable question is:
Specific and testable enough to gather data on
Vague and impossible to answer
Never based on prior observation
Always about opinions, not evidence
2. A hypothesis is:
A reasoned, testable prediction
A random guess with no reasoning
A definite, proven fact
Something that can never be tested
3. Hypotheses are often structured as:
"If... then..."
"Maybe... possibly..."
A single word
A question with no prediction
4. "Is nature good?" is a poor investigable question because it is:
Too vague and not testable with data
Perfectly specific and testable
The best possible scientific question
Already answered by all scientists
5. A hypothesis should be based on:
Existing knowledge and reasoning
Pure random chance
No prior information at all
Guessing with no explanation
6. Noticing an unexpected pattern can:
Spark a good investigable question
Never lead to a scientific question
Only happen by accident with no value
Prevent forming a hypothesis
7. A good hypothesis should be:
Testable and potentially provable wrong
Impossible to test under any circumstances
Always assumed to be true with no testing
A vague feeling with no structure
8. Why is "does more sunlight increase plant height?" a better investigable question than "is nature good?"
It is specific and can be tested by measuring plant height under different sunlight conditions
Both questions are equally testable
"Is nature good?" is more specific and scientific
Investigable questions should never be measurable
9. Why must a hypothesis be potentially provable wrong (falsifiable) to be genuinely scientific?
If no possible result could ever disprove it, it can't be meaningfully tested by evidence
Hypotheses should never be capable of being proven wrong
Falsifiability has no connection to whether something is scientific
A hypothesis is only useful if it can never be tested
10. The hypothesis "if a plant receives more sunlight, then it will grow taller, because sunlight is needed for photosynthesis" includes:
A testable prediction with reasoning behind it
No reasoning at all
A vague, untestable guess
A statement with no prediction
11. Why might reviewing prior research or observations before forming a hypothesis lead to a stronger prediction?
Existing knowledge helps ground the prediction in reasoning rather than a blind guess
Prior research always makes predictions less accurate
Hypotheses should always ignore any existing knowledge
Prior observations have no useful role in forming hypotheses
12. Which of these is a testable investigable question?
Does adding fertiliser increase tomato plant yield?
Are tomatoes tasty?
Is gardening fun?
Should everyone grow tomatoes?
13. Why might a vague question like "is nature good?" be difficult to turn into a testable hypothesis?
"Good" is subjective and not something you can measure or test with data
"Good" is easily and objectively measurable with a single number
Vague questions are always easier to test than specific ones
This question requires no reasoning to answer scientifically
14. A hypothesis differs from a simple guess mainly because a hypothesis:
Is based on reasoning and existing knowledge, and can be tested
Is always correct by definition
Requires no evidence or reasoning at all
Can never be wrong once stated
15. Why might scientists sometimes revise their investigable question after initial background reading or observation?
Early research may reveal the original question needs narrowing, clarifying, or was based on a misunderstanding
Investigable questions should never be revised once first written
Background research never influences how a question should be framed
A first-draft question is always the most refined, final version
16. Why is "if... then... because..." a particularly useful hypothesis structure, compared to just "if... then..."?
Including "because" forces you to state the underlying reasoning, which can also be evaluated and tested
Adding "because" makes a hypothesis less scientific
Reasoning should never be included in a hypothesis
The "because" clause has no scientific value
17. Why might two scientists studying the same phenomenon propose different hypotheses to test?
Different existing knowledge, reasoning or observations can lead to different plausible, testable predictions
Only one correct hypothesis can ever exist for any given phenomenon
Hypotheses are always identical regardless of the scientist's reasoning
Different hypotheses about the same topic are always evidence of an error
18. A hypothesis predicts a plant will grow taller with more sunlight, but the experiment finds no difference. What should happen next?
The hypothesis should be reconsidered or revised in light of the unsupported prediction, not the data ignored
The data should be ignored to preserve the original hypothesis
This result proves the entire scientific method doesn't work
A hypothesis being unsupported means the experiment was worthless
19. Why might turning a broad area of curiosity (e.g. "I wonder about plant growth") into a specific investigable question be one of the hardest, most important steps of an investigation?
A well-framed question focuses the entire investigation and determines what data can actually be meaningfully collected
Broad curiosity is always just as useful as a specific question for planning an investigation
The framing of a question has no effect on how an investigation proceeds
Specific questions are always easier to think of than broad areas of interest
20. A student's hypothesis is "sunlight is good for plants." Why is this weaker than "if a plant receives more sunlight, then it will grow taller, because sunlight is needed for photosynthesis"?
The first is vague and hard to test directly, while the second makes a specific, measurable, falsifiable prediction with reasoning
Both hypotheses are equally specific and testable
A hypothesis should never include reasoning about why it might be true
"Good for plants" is precise enough to design a fair experiment around
21. Understanding how to form investigable questions and testable hypotheses mainly helps you to:
Structure a scientific investigation so it can genuinely be tested and potentially prove an idea wrong
Assume every question is equally scientific regardless of how it is phrased
Avoid ever using reasoning when making a prediction
Treat guesses and hypotheses as exactly the same thing
Answer key (parent copy)
1. Specific and testable enough to gather data on
2. A reasoned, testable prediction
3. "If... then..."
4. Too vague and not testable with data
5. Existing knowledge and reasoning
6. Spark a good investigable question
7. Testable and potentially provable wrong
8. It is specific and can be tested by measuring plant height under different sunlight conditions
9. If no possible result could ever disprove it, it can't be meaningfully tested by evidence
10. A testable prediction with reasoning behind it
11. Existing knowledge helps ground the prediction in reasoning rather than a blind guess
12. Does adding fertiliser increase tomato plant yield?
13. "Good" is subjective and not something you can measure or test with data
14. Is based on reasoning and existing knowledge, and can be tested
15. Early research may reveal the original question needs narrowing, clarifying, or was based on a misunderstanding
16. Including "because" forces you to state the underlying reasoning, which can also be evaluated and tested
17. Different existing knowledge, reasoning or observations can lead to different plausible, testable predictions
18. The hypothesis should be reconsidered or revised in light of the unsupported prediction, not the data ignored
19. A well-framed question focuses the entire investigation and determines what data can actually be meaningfully collected
20. The first is vague and hard to test directly, while the second makes a specific, measurable, falsifiable prediction with reasoning
21. Structure a scientific investigation so it can genuinely be tested and potentially prove an idea wrong