What is an inquiry activity?
An inquiry is when you find an answer by looking, measuring and thinking, instead of only reading it. You are like a scientist. You ask a question, collect evidence (facts you can check) and then explain.
The ocean is a good place for inquiry because there is so much to ask: Why is the sea salty? Where do fish gather? How do waves change with wind? How does plastic move on the shore?
Choosing a good question
A good question can be tested with things you can measure or count. Compare:
- Weak: Is the sea beautiful? (opinion, no measurement)
- Good: Does the water get colder as depth increases? (you can measure)
A hypothesis is your best guess before testing. Example: I think deeper water is colder because sunlight reaches only the top. A guess may turn out wrong, and that is fine.
Planning a fair test
In a fair test you change only one thing and keep the rest the same.
- Variable you change (independent): the depth.
- Variable you measure (dependent): the temperature.
- Variables you keep the same: the same thermometer, the same place, the same waiting time, the same time of day.
Also plan the tools (thermometer, rope with marks, a notebook), the safety (life jacket, adult with you, calm weather) and how many times you will repeat. Repeating gives more trust in your numbers.
Measuring and recording
Read the instrument carefully and write the number with its unit at once. Do not trust your memory.
| Depth (m) | Temperature (°C) |
|---|---|
| 0 | 28 |
| 5 | 27 |
| 10 | 25 |
| 20 | 20 |
| 40 | 14 |
This is sample data to show the idea. A table is the first record. A bar chart or line graph makes the pattern easier to see. Put the changed variable (depth) on the x-axis and the measured one (temperature) on the y-axis.
Finding the pattern and sharing
Look at the graph. In our data, every time the depth grows, the temperature falls. We can say: the deeper the water, the colder it is. We use the data to say it, not just a feeling.
Then ask: does my result match my hypothesis? What could be wrong (a shaky reading, a windy day)? What would I test next, for example the same test in winter?
Share with a short report: question, what you did, a table or graph, the pattern and what you learned. Use simple words and show the evidence.
Ideas for your own ocean inquiry
- How does the amount of salt change how fast an egg floats in water?
- How does water clearness change with depth (use a white disc on a rope)?
- How many kinds of living things live in one square metre of rock pool?
- How far do waves push sand in one hour?
- How much plastic is on 10 metres of beach?
Try it: in the 3D, guess the temperature at 30 m first, then slide to 30 m and check. Was your guess close?
Key formulas and definitions
- Mean = sum of readings / number of readings
- Change = later value - earlier value
- Rate of change = change in temperature / change in depth
- Fair test: change 1 variable, keep the others the same
Worked examples
1. A student measures sea temperature three times at 10 m: 24, 25 and 26 °C. What is the best single value?
Mean = (24 + 25 + 26) / 3 = 75 / 3 = 25 °C.
2. Using the table (28 °C at 0 m, 14 °C at 40 m), by how much did the temperature fall?
Fall = 28 - 14 = 14 °C over 40 m.
3. In the same table, find the average fall per metre between 0 m and 40 m.
14 °C / 40 m = 0.35 °C per metre.
4. A group tests whether salt changes how fast ice melts in water. They use a big cup for salt water and a small cup for plain water. What is wrong?
The cup size is a second change, so the test is not fair. They should use the same cups, the same amount of water and the same start temperature.
Common mistakes
- Changing two things at once, so you cannot tell which one caused the result.
- Writing numbers without units. 25 what? Always write 25 °C or 10 m.
- Taking one reading only. Repeat and find the mean.
- Saying a result is wrong because it did not match the guess. A real result is valuable even when the hypothesis was wrong.