Welcome to Working Scientifically (Years 5 and 6)
Have you ever wondered how scientists figure out how the world works? They do not just guess! Scientists are like detectives who ask questions, gather clues, test their ideas, and carefully check their evidence. In Years 5 and 6, you will learn the exact skills and methods that real scientists use every day.
Don't worry if scientific experiments sound a bit tricky at first. We will break down every skill into simple, bite-sized steps so you can plan, measure, record, and explain like a pro!
1. Planning Enquiries: The 5 Types of Scientific Investigation
A big mistake many people make is thinking that every science experiment must be a "fair test" in a laboratory. In real science, there are actually five different types of enquiry. Choosing the right one depends on the question you want to answer!
The 5 Statutory Enquiry Types:
1. Observing changes over different periods of time (Observing over time): Watching how something changes across minutes, hours, days, or months.
Example: Watching a puddle evaporate in the sun or tracking how a plant grows over four weeks.
2. Noticing patterns (Pattern seeking): Looking for links or relationships between things that you cannot easily control.
Example: Investigating if taller pupils have larger hand spans, or if people who run faster have a higher resting heart rate.
3. Grouping and classifying things (Identifying and classifying): Sorting objects, living things, or materials into groups based on their features.
Example: Sorting rocks by their hardness or classifying animals into vertebrates and invertebrates using branching keys.
4. Carrying out comparative and fair tests: Testing how changing one specific thing alters something else while keeping everything else strictly the same.
Example: Testing which parachute size falls the slowest, or finding which material is the best thermal insulator for a warm drink.
5. Finding things out using secondary sources (Research): Using reliable books, scientific websites, videos, and articles to answer questions that you cannot easily test yourself in class.
Example: Researching the distances of planets from the Sun or finding out what extinct animals ate.
Memory Trick: Think of the acronym P-O-R-C-C to remember all 5:
Pattern seeking | Observing over time | Research | Classifying | Comparative & fair testing.
Key Takeaway: Science is not just fair testing! Scientists pick the best enquiry type to suit the specific question they are trying to answer.
2. Mastering Fair Testing: Variables
When you do plan a comparative or fair test, you need to understand variables. A variable is simply anything that can change or be changed in an experiment.
The Three Key Variables:
1. Independent Variable (What YOU change):
This is the one single factor that you choose to change to see what happens.
Memory tip: I change the Independent variable!
2. Dependent Variable (What YOU measure):
This is the factor that changes because of what you did. It provides your data and measurements.
Memory tip: The Dependent variable gives you your Data!
3. Control Variables (What stays the SAME):
These are all the other factors that you must keep exactly the same throughout the experiment. If you do not keep them the same, your test is not fair, and you will not know what caused your results.
Let's look at an example:
Question: Does the surface material affect how far a toy car rolls down a ramp?
• Independent Variable: The surface material on the ramp (e.g., carpet, wood, foil).
• Dependent Variable: The distance the car rolls along the floor (measured in centimetres using a tape measure).
• Control Variables: The height of the ramp, the toy car used, the release point, and how the car is released (let go, not pushed!).
Common Mistake to Avoid: Never change more than one independent variable at the same time! If you change the ramp height and the surface material at once, you will not know which one caused the car to go further.
Key Takeaway: Change only one thing (independent), measure the effect (dependent), and keep everything else the same (controls).
3. Taking Accurate and Precise Measurements
In Years 5 and 6, you will use a wide range of scientific equipment to collect numbers and measurements with increasing accuracy and precision.
Equipment You Will Use:
• Stopwatches: To measure time accurately in seconds and fractions of a second.
• Thermometers (digital and analogue): To measure temperature in degrees Celsius (\(^{\circ}\text{C}\)).
• Newtonmeters (Force meters): To measure pulling forces and weight in newtons (\(\text{N}\)).
• Measuring Cylinders: To measure liquid volume in millilitres (\(\text{ml}\)).
• Data Loggers: Electronic sensors that measure light, sound, or temperature automatically over time.
Accuracy vs. Precision: What is the difference?
• Accuracy: How close your measurement is to the true, real value.
• Precision: How detailed and finely scaled your measurement is, and how close repeated measurements are to one another.
Example: A digital thermometer that reads \(21.4^{\circ}\text{C}\) gives a more precise reading than one that only shows whole degrees like \(21^{\circ}\text{C}\).
Why Must We Repeat Readings?
Scientists rarely test something just once. Taking repeat readings (doing the same test two or three times) helps you:
1. Check that your results are reliable and repeatable.
2. Spot any anomalies (an odd result that does not fit the pattern, often caused by a mistake or slipping equipment).
3. Calculate an average to get a more trustworthy result.
Key Takeaway: Always read scales at eye level, use the most precise tool available, and repeat your measurements to make sure your results are reliable.
4. Recording and Presenting Data Clearly
Once you collect your observations and numbers, you need to share them clearly so others can understand them.
Ways to Record Your Data:
• Scientific Diagrams: Clear, two-dimensional line drawings with sharp pencil lines and straight label lines pointing directly to the parts (drawn with a ruler, no arrows!).
• Classification Keys: Branching charts with 'yes/no' questions used to identify living things or materials based on observable characteristics.
• Data Tables: Organised grids where the independent variable is in the first column and the dependent variable (measurements) is in the next columns, with clear headings and units of measurement.
Bar Graphs vs. Line Graphs: Which one should you draw?
Choosing the right graph is an essential skill in Upper Key Stage 2!
Use a Bar Graph for Categorical / Discrete Data:
Use a bar graph when your independent variable is made of distinct words, categories, or separate groups that are not continuous numbers.
Examples: Types of materials (wood, metal, plastic), eye colours, or types of shoes.
Tip: Leave a clear gap between each bar!
Use a Line Graph for Continuous Data:
Use a line graph when both variables are continuous numbers that can take any value, especially when tracking changes over time or distance.
Examples: Water temperature cooling over \(20\) minutes, or heart rate measured every minute during exercise.
Tip: Plot your points with small neat crosses (\(\times\)) and connect them with straight ruler lines.
Key Takeaway: Words or separate groups = Bar Graph. Numbers changing smoothly over time/distance = Line Graph.
5. Predictions, Models, and Conclusions
Making Scientific Predictions
A scientific prediction is not a wild guess. It is a thoughtful statement about what you expect will happen, based on previous test results, scientific knowledge, or simple models.
Example: "Based on our last test where thicker wires reduced lamp brightness, I predict that doubling the wire length will make the bulb even dimmer."
Using Scientific Models
Scientists often use simple models to help describe and explain ideas that are too big, too small, or too hidden to see directly.
Examples: Using a globe and a torch to model day and night on Earth, or pretending to be flowing electrons to model an electrical circuit.
Writing Strong Conclusions and Explaining Causation
When writing your final conclusion, you must do three things:
1. State what you found out: Describe the pattern or trend in your data.
2. Provide evidence: Quote your actual numbers and measurements to back up your statement.
3. Explain the science (Causal Relationship): Explain why one thing caused another to happen using scientific vocabulary.
Did you know? Science never says a theory is "proven forever"! Instead, we say that evidence supports or refutes (disproves) an idea. As new tools are invented and new evidence is discovered, scientific ideas change and develop over time.
Key Takeaway: Always back up your conclusions with real numbers from your investigation and use scientific reasons to explain why it happened.
Quick Review: Working Scientifically Checklist
Before finishing any investigation, ask yourself these quick questions:
• Did I choose the best enquiry type (Pattern seeking, Observing over time, Research, Classifying, or Fair testing)?
• In a fair test, did I change only one independent variable and control all the rest?
• Did I take repeat readings to spot anomalies and make sure my results are reliable?
• Did I choose the right graph (Bar graph for categories; Line graph for continuous changes over time)?
• Does my conclusion use evidence (measurements) to support or refute my prediction?