Key Experimental Skills Tested (Copy)

1. Measurement Skills

What You’ll Be Asked:

• “What instrument would you use to measure this?”
• “Record the measurement shown in the diagram.”
• “Estimate the uncertainty in this reading.”

 Key Instruments & Their Uses:

✔️ Tips:

• Quote readings with correct decimal places
• Always include units
• For repeated readings, average them for more reliable results

2. Observation Skills

 What You’ll Be Asked:

• “What do you observe in this experiment?”
• “Describe the change in… as this variable increases.”

Examples of Observations:

• “As the mass increases, the extension of the spring increases.”
• “The temperature rises rapidly in the first 2 minutes, then levels off.”
• “The image becomes smaller and inverted as object distance increases.”

✔️ Tips:

• Use quantitative descriptions when data is given
• Always relate the trend to a variable (e.g. “as time increases…”)
• Avoid vague phrases like “It changes” — always specify what and how

 3. Graphical Skills

 What You’ll Be Asked:

• “Plot a graph of…”
• “Label axes with appropriate units.”
• “Determine the gradient of the line.”
• “What does the graph tell you about the relationship?”

Types of Graphs:

✔️ Tips:

• Use at least half the graph space
• Choose even scale (1, 2, 5, 10…)
• Label axes with quantity + unit
• Plot points with (×) or ●, not random dots
• Use line of best fit only when data is expected to follow a trend

4. Recording and Tabulating Results

 What You’ll Be Asked:

• “Complete the table using your readings.”
• “State the average value of the measurements.”
• “Suggest a heading for the missing column.”

Example Table:

✔️ Tips:

• Always include headings with units
• Align decimal places
• Leave no empty rows or merged units (e.g. cm/s in data box — keep in heading)

 5. Designing Experiments

 What You’ll Be Asked:

• “Describe an experiment to measure…”
• “How would you investigate the effect of…?”

Must Include:

• Variables:
  → Independent (what you change)
  → Dependent (what you measure)
  → Control (what you keep constant)
• Apparatus list
• Step-by-step method
• Data collection format
• Safety precaution

✔️ Tips:

• Use bullet points or numbering
• Quote exact quantities (e.g. “25.0 cm³”, “every 30 seconds”)
• Always mention repeat and average for reliability

6. Interpreting Results

 What You’ll Be Asked:

• “What conclusion can you draw?”
• “Does the data support the hypothesis?”

Example:

“As the voltage increases, the current also increases. The graph is a straight line through the origin.”
✅ Conclusion: Ohm’s law is obeyed. Voltage is directly proportional to current.

✔️ Tips:

• Use words like: directly proportional, inversely proportional, constant, increasing at decreasing rate
• Always base your answer on evidence in the data/graph
• Quote numerical values or trends

7. Identifying and Reducing Errors

 What You’ll Be Asked:

• “What error may occur in this experiment?”
• “How can it be reduced?”

Examples:

✔️ Use specific error types, not just “human error”

8. Suggesting Improvements

 What You’ll Be Asked:

• “Suggest one way to improve the accuracy/reliability of the experiment.”

✔️ Use:

• “Repeat readings and take average”
• “Use digital instruments for more precise values”
• “Reduce external disturbances (e.g. wind, vibrations)”
• “Measure using more sensitive scale or finer divisions”

 9. Stating Safety Precautions

 What You’ll Be Asked:

• “State one precaution to make this experiment safe.”

✔️ Always match safety to the risk in the experiment