Data Presentation Methods
Graphical, visual & cartographic presentation techniques
Raw numbers in tables
Hard to see patterns
Graphs & maps
Make patterns visual
Right method
Suits data type
Choose the most appropriate presentation method for each scenario
"Pedestrian count at 8 different locations in a city"
Which presentation method is most appropriate?
1. Bar Charts
Shows: Compare discrete categories (separate, unconnected data)
Use when: Comparing footfall at locations, EQS scores between sites, traffic at different times
How to draw:
- X-axis: Categories (Location A, B, C)
- Y-axis: Values (scale from 0, equal intervals, labeled)
- Bars: Same width, gaps between (not touching)
2. Histograms
Shows: Frequency distribution of continuous data
Use when: Pebble size distribution, building age distribution
Key difference from bar chart:
- Bars touching (continuous data)
- X-axis = continuous scale (0-2cm, 2-4cm sizes)
- Y-axis = frequency (how many)
3. Line Graphs
Shows: Trends over continuous data (time or distance)
Use when: River depth downstream, temperature over time, beach profile
Multiple lines: Plot two variables on same graph with different colors
4. Scatter Graphs
Shows: Relationship between two variables
Use when: Testing correlations (e.g., does pedestrian count decrease with distance?)
Positive
X↑ Y↑
Negative
X↑ Y↓
None
Random
5. Pie Charts
Shows: Proportions (parts of a whole) - must total 100%
Use when: Land use percentages, traffic composition
Calculate angles:
(Category value / Total) × 360°
Example: 40% = (40/100) × 360 = 144°
6. Dispersion/Box Plots
Show range & spread (min, max, median, quartiles). Compare variation between sites.
7. Population Pyramids
Age-sex structure. ONLY for population data (urban vs rural comparison).
Learn to construct a bar chart step by step
Raw Data: Pedestrian Count Survey
X-axis for categories (locations), Y-axis for values (count)
Identify correlation patterns and practice drawing lines of best fit
Distance from center vs. Land price
What type of correlation does this show?
Learn to calculate angles for pie chart segments
Formula:
Angle = (Category value / Total) × 360°
Land Use Data:
| Category | % |
|---|---|
| Residential | 40% |
| Retail | 30% |
| Industrial | 20% |
| Other | 10% |
| Total | 100% |
Pie Chart Limitations:
- • Hard to compare precise values between segments
- • Only suitable for small number of categories (3-6)
- • Cannot show trends over time
- • Must total 100% (parts of a whole)
8. Choropleth Maps
Color/shading shows density across areas
Use: Population density, forest cover %, deprivation index
9. Isoline Maps
Lines connect points of equal value
Use: Contours, isotherms (temperature), isobars (pressure)
10. Dot Maps
Dots show distribution (1 dot = fixed quantity)
Use: Population distribution, tree locations
11. Proportional Symbols
Symbol size shows quantity (area proportional)
Use: Pedestrian counts at sites, tourist arrivals
12. Flow Lines/Desire Lines
Show movement between locations (thickness = volume)
Use: Traffic flow, migration patterns, trade routes
Click regions to see population density data (people per km²)
Legend (people/km²)
Choropleth Limitations:
- • Sharp boundaries imply sudden change (actually gradual)
- • Whole area same shade (variation hidden within)
- • Large areas dominate visually even if low population
13. Annotated Photos
Visual evidence with labels explaining features
Include: Arrows to features, explanatory labels, evidence statements
14. Field Sketches
Simplified drawing highlighting key features
Must include: Title, location, date, compass direction, labels
15. Word Clouds
Word size shows frequency from questionnaire responses
Larger words = mentioned more often
Decision Factors:
- Data type: Continuous or discrete? Quantitative or qualitative?
- Purpose: Comparison, trend, relationship, distribution, proportion?
- Audience: Simple for clarity vs complex for detail
Grade 8/9 Tips:
- • Use multiple methods for same data (map + graph)
- • Justify choice in exam ("Bar chart appropriate because...")
- • Be ready to adapt/complete partly-finished graphs
Question 1 of 6 | Score: 0
What is the key difference between a bar chart and a histogram?
Suggest an appropriate method to present data showing how pebble size changes with distance along a beach. Justify your choice. (3 marks)