D. Composition: Expressing Ideas and Creating Texts · Writing with Purpose: Research, Essays, Media and PublishingExpository and Informational Writing: Reports, Explanations and Data
D2.1About 70 minutes
Learning goals- I can tell expository and informational writing apart from argument, and keep an objective, precise tone.
- I can draft an informational report with an introduction, headed sections, text features and cited sources.
- I can write a clear explanation of a process or a cause and its effects, defining key terms.
- I can transform information from one form to another, such as turning data into a graph and a graph into a clear paragraph.
Words to know
expository writing
Writing that explains how or why something works or happens.
informational text
A text whose main purpose is to give accurate facts about a topic, such as a report or a news article.
objective
Based on facts and evidence rather than personal feelings or opinions.
text features
Parts of a text that help readers navigate it, such as headings, captions, bold terms, lists, sidebars and graphs.
transform
To change information from one form to another, for example from a table into a graph, or from a graph into words.
definition paragraph
A paragraph that explains a key term clearly, often with an example and what it is not.
data
Facts and numbers collected for study, such as survey results or measurements.
Remember from Grade 8
In Grade 8 you wrote news articles with the inverted pyramid, turned data into graphs and infographics, and learned to spot misleading graphs.
In Grade 9 you'll write the longer informational and expository texts that other subjects ask for too: lab reports in science, case studies in geography, research reports in history. The skills here transfer directly.
Explain, inform or argue?
- Informational writing gives accurate facts: What is the situation? (a report on how students travel to school)
- Expository writing explains: How does it work? Why does it happen? (why fewer students bike in winter)
- Argument takes a position: What should we do? (the city should clear bike lanes in winter)
Informational and expository texts are objective: they don't tell the reader what to think. Watch for opinion words sneaking in (sadly, obviously, terrible, amazing) and replace them with facts and precise language.
Opinionated: Sadly, way too many kids get driven to school in winter.
Objective: In February, 42 of the 150 students surveyed were driven to school, compared with 30 in October.
Transforming information
The curriculum asks you to use media, tools and strategies to transform information. That means choosing the best form for each piece of information:
- Numbers that compare groups become a bar graph.
- Change over time becomes a line graph or timeline.
- Parts of a whole become a circle graph (only if the parts add to 100%).
- Steps in a process become a numbered list or flowchart.
- A dense paragraph may become a table for quick comparison.
Transforming goes the other way too: a good report also explains the graph in words, because readers need to know what to notice.
Worked exampleLet's turn a graph into a clear paragraph
Write an objective paragraph explaining the bar graph above for a report titled Getting to School in an Ontario Winter.
- Topic sentence (the main pattern): Students' ways of getting to school changed between October and February.
- Biggest changes, with exact numbers: The number of students who biked fell from 12 to 2, and the number who were driven rose from 30 to 42.
- Other changes: Bus riders increased from 60 to 66, while walkers decreased from 48 to 40.
- Possible explanation, carefully worded (expository): These changes are likely connected to winter conditions, such as snow-covered bike lanes and colder temperatures, although the survey did not ask students for their reasons.
- Source: (Class 9B Survey).
Students' ways of getting to school changed between October and February. The number of students who biked fell from 12 to 2, and the number who were driven rose from 30 to 42. Bus riders increased from 60 to 66, while walkers decreased from 48 to 40. These changes are likely connected to winter conditions, such as snow-covered bike lanes and colder temperatures, although the survey did not ask students for their reasons (Class 9B Survey). Every number matches the graph, and the explanation is labelled as likely, not proven.
Text features (headings, visuals with captions, lists and a source list) help readers find and understand information quickly. Each is a choice that serves the reader.Explaining a process or a cause
For a process, use chronological order, number the steps if it's instructions, and use transitions such as first, next, once, after, finally. For cause and effect, use transitions such as because, as a result, therefore, this leads to, consequently, and be careful not to claim a cause you can't prove (see the word likely above).
Define key terms the first time you use them, especially for a general audience. A strong definition paragraph gives the term, its category, what makes it different, and an example: Freeze-thaw weathering is a type of physical weathering (category) in which water seeps into cracks, freezes, expands and widens the crack (difference). It's one reason Ontario roads develop potholes each spring (example).
Precise language checklist
- Replace vague words: a lot, stuff, things, very, really with exact numbers and nouns.
- Use subject-specific vocabulary and define it.
- Prefer active verbs: Volunteers flood the rink instead of The rink is flooded by volunteers (unless the doer doesn't matter).
- Cite every fact that isn't common knowledge, and every graph or image you didn't make.
Hands-on activityHousehold data report
Collect a small set of data at home over a week, for example: how many minutes each family member spends outdoors each day, the outdoor temperature each morning, or how many items go in the recycling versus garbage.
- Record it in a table.
- Transform it into a graph (bar or line) drawn by hand or with a spreadsheet. Give it a title, labelled axes and a source note.
- Write a one-page informational report with a title, a short introduction, two headed sections, your graph with a caption, and a conclusion that states the main pattern.
- Read it aloud and remove any opinion words.
What to look for: numbers in the paragraphs match the graph exactly, and possible causes are worded carefully (likely, may).
Just for funFreeze-thaw weathering is one reason Ontario has a fifth season. Winter, spring, summer, fall... and pothole.
Your turn
1Informational, expository or argument? (a) How freeze-thaw creates potholes. (b) The city must fix potholes faster. (c) A report on how many potholes were repaired in 2025.
(a) expository (explains how); (b) argument; (c) informational.
2Rewrite objectively: The amazing new library is way better than the old dump.
Example: The new library has 40 computer stations and twice the floor space of the previous building. (facts instead of judgments; invented numbers)
3Which graph would you use for: (a) temperature each day for a month; (b) favourite winter sport among 4 choices; (c) how a 24-hour day is divided (sleep, school, other)?
(a) line graph (change over time); (b) bar graph (comparing groups); (c) circle graph (parts of a whole adding to 100%).
4Using the graph in this lesson, how many more students took the bus in February than in October?
66 − 60 = 6 more students.
5Write a definition paragraph sentence for carpool using term + category + difference.
Example: A carpool is a travel arrangement in which several people who are going to the same place share one car.
6Name four text features of an informational report.
Any four: title, headings, subheadings, bold terms, captions, graphs or images, bulleted or numbered lists, sidebars, table of contents, works cited.
More practice: warm-up
1What does objective mean?
Based on facts and evidence, not personal feelings or opinions.
2What kind of graph shows change over time?
A line graph (or a timeline).
3Name two transition words for cause and effect.
Any two: because, as a result, therefore, consequently, this leads to, so.
4In the bar graph, how many students biked in October?
5Should a report's paragraphs explain its graphs?
Yes: readers need to know what to notice.
More practice: on your own
1Check the graph: do the February numbers add to 150?
40 + 66 + 42 + 2 = 150. Yes.
2A student writes, Because it was snowing, 10 more students were driven to school. What's wrong with this claim?
The survey didn't ask for reasons, so snow can't be stated as the proven cause. (Also, the actual increase was 12: 42 − 30.) Better: 12 more students were driven in February, likely because of winter weather.
3Transform these steps into a numbered list: You need to clear the snow before you lay the tarp, and after the frame is built you add water slowly in layers once the tarp is in.
- Clear the snow. 2. Build the frame. 3. Lay the tarp. 4. Add water slowly, in layers. (The order follows the logic of the instructions: the frame holds the tarp, so it comes before it.)
4Write two headings for a report titled Ontario's Spring Maple Syrup Season.
Examples: How Sap Becomes Syrup and Why Weather Matters for the Sap Run.
5A circle graph shows 45% bus, 30% walk, 20% car. What's wrong?
The parts add to 95%, not 100%. Either a category (e.g. bike or other, 5%) is missing, or the data is wrong.
Challenge
1Write an objective expository paragraph (4 sentences) explaining why outdoor rinks need several cold days in a row to open. Use cause-and-effect transitions.
Example: Outdoor rinks are built by spraying thin layers of water that must freeze solid one at a time. Because each layer needs time below freezing, a single cold night is not enough to build a thick, safe surface. As a result, volunteers usually wait for a stretch of cold days before flooding. If temperatures rise above freezing, the surface softens and can crack, so the process may have to start again. Look for objective language, a clear causal chain and transitions.
2Explain how the same survey data could appear in an informational report and in an argument, and how the writing would differ.
In the report, the data is presented objectively to describe the pattern. In an argument, the writer selects the most relevant data (e.g. the drop in biking) as evidence for a claim (e.g. the city should clear bike lanes) and adds reasons and a call to action. The numbers are the same; the purpose changes how they're used.
3A graph's vertical axis starts at 35 instead of 0, making the February bus bar (66) look about six times taller than the February walking bar (40). Explain the problem and how to fix it.
Starting the axis at 35 exaggerates differences (a misleading graph): above 35, the bars are 31 and 5 units tall, but 66 is not six times 40. Fix: start the axis at 0, or clearly mark a broken axis and explain it.
Quiz
1. Which sentence is objective?
2. Expository writing mainly:
3. Best graph for comparing four groups at one time:
4. In the lesson's graph, the biggest drop from October to February was in:
5. Which is the best way to describe a possible cause that the data doesn't prove?
6. A strong definition includes:
Informational and expository writing is used in every high school subject. Help your teen notice how real reports (from Statistics Canada, a city council, a health unit) use headings, graphs and captions.
Common difficulties: slipping opinion words into reports; numbers in the text that don't match the graph; claiming causes the data can't prove; graphs without titles, labels or sources. A quick check: ask your teen to point to where each number in their paragraph appears in their graph or table.