OCR AAQ Applied Science F181 • Unit 2.3.2

Presenting Scientific Data

Choosing, drawing and checking scientific graphs

By the end

You should be able to…

  • Identify key features and uses of different graph types.
  • Choose a suitable graph for a dataset.
  • Explain why different graphs suit different data and audiences.
  • Spot common errors in scientific graphs.
  • Draw accurate graphs from example data.
MWB: Why do scientists use graphs?

Write two reasons.

Core idea

The graph depends on the data

Categories?

Use bar charts or pie charts when you have groups, types or proportions.

Continuous values?

Use line graphs, scatter graphs, histograms, cumulative graphs or box plots.

Pattern across space?

Use specialised graphs such as kite diagrams for abundance along a transect.

Interactive graph hub

Click each graph type for information and a diagram

🔵Scatter graphRelationship between two continuous variables
📈Line graphChange over a continuous variable
📊Bar chartCompare categories
▥HistogramGrouped continuous frequency
🥧Pie chartProportions of a whole
🪁Kite diagramAbundance along a transect
📉Cumulative graphRunning total
📦Box-and-whiskerMedian, quartiles and range
Summary table

Which graph, when?

Graph typeKey featuresWhen used
Scatter graphPoints plotted; may include line of best fit.Relationship/correlation between two continuous variables.
Line graphPoints joined to show trend.Continuous data changing over time or another continuous variable.
Bar chartSeparate bars with gaps.Comparing categories or discrete groups.
HistogramBars touch; grouped continuous data.Frequency distribution of continuous measurements.
Pie chartCircle divided into sectors.Proportions or percentages of a whole.
Kite diagramSymmetrical shapes along a transect.Distribution or abundance of species along an environmental gradient.
Cumulative graphRunning total curve.Cumulative frequency or total over time/range.
Box-and-whisker plotMedian, quartiles, range and possible outliers.Comparing spread and central tendency between datasets.
Which graph when?

Scenario challenge

Press start to begin.

Spot the errors

Click an error card. Students identify the problem, then reveal the answer.

⚠️Error 1Click to inspect the graph.
⚠️Error 2Click to inspect the graph.
⚠️Error 3Click to inspect the graph.
⚠️Error 4Click to inspect the graph.
⚠️Error 5Click to inspect the graph.
⚠️Error 6Click to inspect the graph.
Randomised graph drawing practice

Each click gives a dataset. Identify the graph type, draw it, then reveal support.

Press “new dataset” to begin.

How-to guide

Top tips for drawing graphs

  1. Choose a graph that matches the data type.
  2. Use a sharp pencil and ruler.
  3. Label both axes and include units.
  4. Choose a sensible scale that uses most of the graph paper.
  5. Plot points accurately.
  6. Use gaps for bar charts, no gaps for histograms.
  7. Draw a sensible line or curve of best fit when appropriate.
  8. Add a clear title if required.

Student task

Create a “how to draw science graphs” guide for another student.

  • which graph to choose and why
  • top tips for accurate graph drawing
  • one common mistake to avoid
  • one worked example

Glossary builder

Click each term and add the definition to your notes.

Exam-style questions

  1. Explain why a bar chart is suitable for blood group data.
  2. Describe two mistakes students often make when drawing graphs.
  3. Explain why a scatter graph may need a line of best fit.
  4. Calculate a pie chart angle for 9 out of 30 students.
Extended work

Advanced graph choices

Kite diagram data

Species abundance is measured every 5 m from the shore to inland.

Distance from shore (m)Sea lavender abundance
02
58
1014
156
201

Box plot data

Compare pulse rates before and after exercise using spread and median.

DatasetMinQ1MedianQ3Max
Before6268727886
After92104116128148

Cumulative data

Seedling heights are grouped into classes and cumulative totals are calculated.

Height less than (cm)Cumulative frequency
53
1012
1525
2034
2540
Finishing quiz

Multiple-choice checkpoint

Answer each question. Your score will appear at the end.