The human nervous system: Students should be able to extract and interpret data from graphs, charts and tables, about the functioning of the nervous system.

The idea

Extracting and interpreting data about the nervous system means reading values accurately from graphs, charts and tables, then using those values to describe or explain nervous function. For example, a graph may show reaction time in milliseconds against a stimulus such as a sound or light. You read the value on the y-axis for a given x-axis value, compare values between conditions, and identify patterns such as a shorter reaction time after practice. You may also calculate a mean from repeated measurements or identify anomalous results. Interpretation goes beyond reading numbers: you link the data to nervous system processes, such as faster impulse transmission or improved coordination, and evaluate whether the evidence supports a conclusion. Always quote units and refer to the data in your answer.

What earns the marks

• Read values accurately from the axes of a graph or from cells in a table, including correct units such as milliseconds (ms) or metres per second (m/s).
• Identify the independent variable and dependent variable in a data set about nervous function.
• Describe patterns or trends, such as reaction time decreasing as a stimulus becomes more intense or after repeated trials.
• Compare data between conditions or groups, quoting specific values to support the comparison.
• Calculate a mean from repeated measurements and identify anomalous results that do not fit the pattern.
• Interpret data in terms of nervous system function, for example linking a shorter reaction time to faster impulse transmission or more efficient coordination.
• Evaluate whether the data support a stated conclusion, recognising limitations such as small sample size or uncontrolled variables.

Common mistakes and how to put them right

• Reading a graph inaccurately, such as using the wrong scale interval.

  Put it right: Check the scale on each axis and count intervals carefully before quoting a value.

• Describing a trend without quoting data.

  Put it right: Support every description with specific values from the graph, chart or table, including units.

• Confusing correlation with causation.

  Put it right: State that the data show a relationship, and only claim causation if the evidence and experimental design support it.

• Ignoring anomalous results when calculating a mean.

  Put it right: Identify anomalies and exclude them from the mean, or comment on their effect.

Exam tips

• Before answering, read the axis labels and units so you quote values correctly.
• When asked to compare, use comparative words such as higher, lower, faster or slower and give values for both conditions.
• If asked to calculate a mean, show your working and include the unit in your answer.
• Use the phrase 'the data show that...' followed by a specific value to make your interpretation clear.