D. Data · Data and Probability

Collecting Data: Primary and Secondary Sources

D1.2 A1About 45 minutes

Learning goals

I can tell the difference between a primary source and a secondary source of data.
I can ask a question of interest that compares two or more groups.
I can organize two sets of data in one frequency table.
I can check whether a secondary source is a good one to use.
I can collect data fairly and respectfully.

Words to know

primary source
Data you collect yourself, first-hand, by asking, watching, measuring or doing an experiment.

secondary source
Data that someone else collected, which you find in a book, a reliable website, a newspaper or a record.

frequency
How many times an answer or a value appears in the data.

frequency table
A table that lists each answer and its frequency.

data set
All the data collected from one group, like all the answers from one class.

Remember from Grade 3

You used tally marks to record data. Each line is 1, and the fifth line crosses the first four to make a bundle of 5. Then you wrote the totals in a frequency table. In Grade 4 you will collect data from different sources and put two or more sets of data side by side so you can compare them.

A question that compares

The Grade 4 class is planning winter fun day with the Grade 1 buddy class. They wonder:

"Do Grade 4 students and Grade 1 students like the same winter activities?"

This question compares two groups. To answer it, they need two sets of data: one from each class. Then they can put the two sets side by side.

Where does data come from?

Primary source: you collect the data yourself, first-hand. You might:

do a survey or an interview
observe and count (birds at a feeder, cars going by)
measure or do an experiment

Secondary source: someone else collected the data, and you use it. You might find it in:

a book, an atlas or a newspaper (like the sports page)
a reliable website, like Statistics Canada, which collects data about people across Canada
weather records, or the school library's records of books borrowed

Two chickadees and a red cardinal eat seeds at a snowy wooden bird feeder. — If you count the birds at your own feeder, you are collecting data from a primary source. AI-generated image

A primary source is data you collect first-hand, like a survey. A secondary source is data someone else collected, like an atlas, the sports page or a reliable website.

	Primary source	Secondary source
Who collects it?	You do	Someone else did
Good points	You ask exactly the question you want. You know how the data was collected.	It is quick. It can have lots of data, or data about places you can't visit.
Watch out for	It takes time. Your group may be small.	It may not answer your exact question. It may be old. Check who made it.

Both kinds of sources are useful. Good data detectives think about which one fits their question.

Worked example

Example 1: Primary or secondary?

Is each one a primary or a secondary source?

You count the birds at your feeder for 10 minutes.
You read the number of goals each player scored in a hockey magazine.
Your class measures the length of shadows in the schoolyard.
Your teacher shows a table of data from Statistics Canada.

1: You collected it yourself: primary.
2: The magazine collected it: secondary.
3: Your class collected it: primary.
4: Statistics Canada collected it: secondary.

1 primary, 2 secondary, 3 primary, 4 secondary.

Two sets of data, one frequency table

The Grade 4 class surveyed itself and then visited the Grade 1 class to ask the same question: "What is your favourite winter activity: skating, sledding, skiing or making snowmen?" This is primary data. Here are their tallies.

Tallies. Grade 4: skating 8, sledding 12, skiing 4, snowmen 6. Grade 1: skating 3, sledding 10, skiing 2, snowmen 11.

Worked example

Example 2: Make a frequency table that compares

Turn the tallies into one frequency table with a column for each class.

Make three columns: Activity, Grade 4 and Grade 1.
Count each row of tallies by 5s, then 1s. Grade 4 sledding: 5, 10, 11, 12 → 12.
Add a Total row for each class. Grade 4: 8 + 12 + 4 + 6 = 30. Grade 1: 3 + 10 + 2 + 11 = 26.
Check: Grade 4 has 30 students and the Grade 1 class has 26, so every answer was counted.

See the frequency table below.

Activity	Grade 4	Grade 1
Skating	8	3
Sledding	12	10
Skiing	4	2
Snowmen	6	11
Total	30	26

Favourite winter activity. Source: our class surveys, January 2026.

Now the comparison is easy to see: sledding is the favourite for Grade 4, and making snowmen is the favourite for Grade 1. Sledding is popular with both classes.

Worked example

Example 3: Data from a secondary source

The school librarian printed the library's records for October. How many books did each grade borrow, and which grade borrowed more sports books?

The librarian's computer collected this data, so it is a secondary source for the class.
Grade 3 total: 24 + 18 + 9 + 6 = 57 books. Grade 4 total: 31 + 12 + 15 + 10 = 68 books.
Sports books: Grade 3 borrowed 9, Grade 4 borrowed 15. 15 − 9 = 6 more for Grade 4.

Grade 3 borrowed 57 books and Grade 4 borrowed 68. Grade 4 borrowed 6 more sports books.

Kind of book	Grade 3	Grade 4
Comics	24	31
Animals	18	12
Sports	9	15
Mystery	6	10
Total	57	68

Books borrowed in October. Source: school library records.

Checking a secondary source

Ask three questions:

Who collected the data? Can I trust them?
When was it collected? Is it too old?
Does it answer my question, or a different question?

Being a fair and respectful data collector

Ask everyone the same question in the same way.
Ask politely, and let people say "I'd rather not answer."
Record every answer, even ones you don't like.
Keep personal answers private: share totals, not who said what.

Just for fun

Why did the bird watcher bring a clipboard to the bird feeder?

Counting birds yourself is a primary source. Asking the birds to fill out a survey did not go well!

Hands-on activity

Kids versus grown-ups survey

You need: paper and a pencil.

Write a question that compares two groups, like "What is your favourite season: winter, spring, summer or fall?"
Make a tally chart with two columns: Kids and Grown-ups.
Ask at least 5 kids and 5 grown-ups (family, neighbours, or friends by phone or video chat with a grown-up's help). This is your primary data.
Make a frequency table with a Total row for each group. Check that each total matches the number of people you asked.
With a grown-up, find a table of data in a newspaper, a sports page, a book or a reliable website. That is a secondary source. Write down who made it and when.

Keep your survey data. You will graph it in a later lesson.

Math talk: "Did kids and grown-ups give the same favourite? What surprised you?"

Fruit	Grade 4 students	Adults
Apples	9	7
Pears	3	5
Grapes	7	4
Plums	2	6

Favourite fall fruit. Use this table for questions 4 to 6.

Your turn

You time how long ice cubes take to melt on your kitchen counter. Primary or secondary source?

You use a table of the populations of Canadian cities from an atlas. Primary or secondary?

Name one good thing and one thing to watch out for when you use a secondary source.

Look at the fruit table. How many Grade 4 students were surveyed?

Which fruits did more adults than students choose?

What was the favourite fruit of each group?

A tally shows 3 bundles of 5 and 2 more lines. What is the frequency?

More practice: warm-up

You interview your grandmother about games she played as a child. Primary or secondary?

You read hockey scores in the newspaper. Primary or secondary?

What does frequency mean?

2 bundles of 5 tally marks and 4 extra lines. What is the frequency?

The frequencies in a table are 6, 4 and 5. How many people answered?

More practice: on your own

Write a survey question that compares two groups.

Ravi asked 25 people a question, but his frequencies are 9, 6 and 7. What went wrong?

Use the library table. How many more comic books did Grade 4 borrow than Grade 3?

Statistics Canada is a good source for how many people live in Ontario. Why is it not a good source for your class's favourite snack?

Your friend found a table of kids' favourite video games from a website made in 2005. What should you think about?

Challenge

Grade 4 has 30 students and 6 chose snowmen. The Grade 1 class has 26 students and 11 chose snowmen. Is it fair to say making snowmen is more popular with Grade 1? Explain.

Fill in the missing number. Grade 4 total: 30. Skating 8, Sledding ?, Skiing 4, Snowmen 6.

Plan a project that compares three groups. Write the question, say whether you will use a primary or secondary source, and list the headings of your frequency table.

Check your understanding

Quiz

You measure how much rain falls in your yard each day. This is a...

Which one is a secondary source?

A frequency table shows 8, 12, 4 and 6. How many people answered?

Which question compares two groups?

Before you use a secondary source, you should check...

4 bundles of 5 tally marks and 3 extra lines show...

For parents and teachers

What this lesson teaches: collecting data from primary sources (your own surveys, observations, measurements) and secondary sources (data someone else collected: books, newspapers, Statistics Canada, library records), asking questions that compare two or more groups, and organizing the data in a frequency table with a column for each group (D1.2). Collecting data fairly and respectfully (A1) is included.

How to help at home:

Help your child find a table in a newspaper, flyer, sports page or reliable website. Ask: "Who made this? When? Can we trust it?"
Be a willing survey participant, and help them reach other grown-ups safely (in person, or by phone or video chat with you).

Common difficulties:

Totals that don't match the number of people asked. Teach the habit of checking the total.
Counting tally bundles as 4 instead of 5.
Trusting any website. Model asking who made it and when.
Privacy: remind your child to share totals, not who said what.