How Bar & Pie Charts Differ from Line Graphs
Bar Chart: Water Usage by Sector
Pie Chart: Same Data as Proportions
What Changes in Your Writing?
| Line Graphs | Bar/Pie Charts |
|---|---|
| Focus on TRENDS (rose, fell, fluctuated) | Focus on COMPARISONS (higher than, the largest) |
| Describe change: "increased from X to Y" | Describe difference: "X was twice as high as Y" |
| Time language: "over the period", "by 2020" | Comparison language: "whereas", "compared to" |
| Overview: main trends | Overview: biggest/smallest, main patterns |
Bar Chart Strategy: Finding the Story
Bar charts can be simple (one set of bars) or complex (grouped/stacked bars comparing multiple things). The key is identifying WHAT to compare.
Decision: What's the Story Here?
Look at the chart. Which observations would make the BEST overview? Select 3.
Pattern across all categories
Specific data point
Overall pattern for one country
Range without insight
Comparative insight
Specific data point
What Makes a Good Bar Chart Overview
INCLUDE:
- Which category was highest/lowest ACROSS all groups
- Overall patterns (one country consistently higher/lower)
- Where differences were biggest/smallest
SAVE FOR BODY PARAGRAPHS:
- Specific dollar amounts
- Individual data points without comparison
Comparison Language for Bar Charts
the highest figure
the largest proportion
the most significant
the lowest amount
higher/lower than
twice/three times as much as
marginally more than
significantly less than
whereas / while
in contrast to
compared to/with
unlike
roughly equal
approximately the same
comparable figures
little difference between
Pie Chart Strategy: Describing Proportions
Energy Sources 2000
Energy Sources 2020
The Special Challenge: Two Pie Charts
When you have two pie charts showing different times, you DO describe change - but the language is different from line graphs.
"Oil increased from 40% to 35%." - This is contradictory! Oil didn't increase.
"Coal rose while renewables fell." - Imprecise and potentially confusing.
"Oil's share declined from 40% to 35%, while renewables grew from a negligible 2% to account for 18% of the total."
"Coal remained the dominant source, though its share fell from 45% to 30%."
Proportion Vocabulary
| Percentage | Alternative Expressions |
|---|---|
| 100% | all / the entire amount / the whole |
| 75% | three quarters / the vast majority |
| 66% | two thirds / the majority |
| 50% | half / equal proportions |
| 33% | one third / a third |
| 25% | a quarter / one in four |
| 10-15% | a small proportion / a minority |
| < 5% | a negligible amount / a tiny fraction |
Practice: Rewrite Using Proportion Language
The sentence below uses weak language. Rewrite it properly.
Weak: "In 2000, coal was 45% and oil was 40%. Gas was 10% and nuclear was 3%. Renewables was 2%."
Model: "In 2000, fossil fuels dominated the energy mix, with coal accounting for nearly half (45%) and oil representing two-fifths of the total. Gas made up a tenth, while nuclear and renewables together comprised only 5%."
Notice: Groups related items, uses fractions, avoids repetitive "was X%"
Decision: How to Organize Your Answer
With bar charts comparing multiple categories across groups, you must decide: organize by CATEGORY or by GROUP?
Which Organization is Better?
"Swimming was most popular among young people (65%) but less so for older groups (30%)...
Reading showed the opposite pattern, with 70% of over-65s participating compared to only 25% of 18-30s..."
"Among 18-30 year olds, swimming was the most popular activity at 65%, followed by gaming at 55%...
The 31-50 age group showed different preferences, with cycling leading at 45%..."
Both Can Work - But Consider This:
Option A (By Activity) is often better when:
- You want to highlight how ONE thing varies across groups
- There are clear patterns (young vs old preferences)
- Fewer activities to discuss
Option B (By Age Group) works when:
- Each group has distinctly different patterns
- You want to paint a picture of each group's behavior
- The question specifically asks about groups
Full Practice: Bar Chart Task
Step 1: Identify Key Features
Before writing, note 3-4 significant patterns:
Step 2: Write Your Overview (2-3 sentences, NO specific data)
Model Overview:
"Overall, there is a clear generational divide in news consumption habits. Younger age groups predominantly rely on digital sources, particularly social media, while older demographics show a strong preference for traditional media such as television and newspapers."
Step 3: Write Body Paragraphs (with specific data)
BODY 1
Social media is the dominant news source for young people, with 72% of 18-29 year olds using it, compared to just 15% of those over 65. Online news websites show a similar pattern, though less pronounced, with usage declining steadily with age from 58% among the youngest group to 22% among the oldest.
BODY 2
In stark contrast, traditional media dominates among older demographics. Television is the primary news source for over three-quarters (78%) of those aged 65+, nearly double the rate for 18-29 year olds (42%). Newspapers show the most dramatic age gap, read by 65% of over-65s but only 12% of the youngest cohort. Radio usage is relatively consistent across age groups, ranging from 25% to 38%.
Full Practice: Pie Charts (Two Time Periods)
Household Waste Disposal 2000
Household Waste Disposal 2020
Write a Complete Answer (150+ words)
Include: Introduction, Overview, Body Paragraph 1 (2000 data), Body Paragraph 2 (2020 data and changes)
INTRODUCTION
The pie charts compare methods of household waste disposal in 2000 and 2020.
OVERVIEW
Overall, there was a significant shift away from landfill towards more sustainable methods, particularly recycling. While landfill remained the largest category in both years, its dominance decreased substantially.
BODY 1
In 2000, landfill was by far the most common disposal method, accounting for nearly two-thirds (62%) of all household waste. Incineration made up approximately a quarter (25%), while recycling represented only a small fraction at 8%. Composting was negligible, comprising just 5%.
BODY 2
By 2020, the picture had changed dramatically. Landfill's share fell by nearly half to 35%, though it remained the largest category. Most notably, recycling increased fourfold to account for almost a third (32%) of waste disposal. Composting also saw significant growth, tripling to 15%, while incineration declined slightly to 18%.
[178 words]
Key Takeaways
- Focus on COMPARISONS between categories/groups
- Use comparative language: "higher than", "twice as much", "the largest"
- Identify which differences are most significant
- Group related categories in body paragraphs
- Use PROPORTION language: "accounted for", "comprised", "made up"
- Vary expression: use fractions (a quarter), not just percentages
- For two pies: describe change in SHARE, not just amounts
- Always note the dominant category and any surprising findings
- Using "increased/decreased" for single-time bar charts
- Describing every single bar or slice (select what's significant)
- Repeating "was X%" for every data point
- Forgetting to compare - just listing numbers separately
- Putting specific percentages in the overview