To show a documented change, pair evidence from near the start with evidence from near the end, about the same dimension, then state the difference. One source shows a moment. Two matched sources, or one table with two dates, show movement.
This lesson follows defining the period and dimension and belongs to the change, continuity and comparison module.
Fact, viewpoint or interpretation?
Keep three things apart when you use evidence.
- Established fact: something the records support, such as a count or a date.
- A source’s viewpoint: what the author believed or wanted the reader to think.
- Historical interpretation: your or a historian’s explanation of what the facts mean.
Change can be proved only with facts. Viewpoints add colour and interpretations add meaning, but neither replaces a record.
How to show a change, step by step
- Choose the dimension you set in your question.
- Find an early piece of evidence near the start date.
- Find a matching late piece near the end date, measuring the same thing.
- State both in one sentence, with the dates.
- State the difference as a size, using numbers when you have them.
- Check the type of measure. Is it a share (percentage) or a number (count)? Do not mix them.
Worked example
Harbourtown is invented, so all figures and quotations below are made up for practice.
Invented table: workers in Harbourtown
| Year | All workers | In fishing | In canning |
|---|---|---|---|
| 1900 | 1,600 | 70% (1,120 workers) | 5% (80 workers) |
| 1950 | 3,600 | 40% (1,440 workers) | 35% (1,260 workers) |
Invented source A (labelled as invented), harbour-master’s note, 1902: “Nearly every household here lives by the boats.”
Invented source B (labelled as invented), council report, 1951: “The cannery is now the town’s largest employer, and the old way of life is fading.”
Step 1, facts from the table. Fishing’s share fell from 70% to 40%, a drop of 30 percentage points. Canning’s share rose from 5% to 35%, a rise of 30 percentage points.
Step 2, check the numbers. The workforce grew from 1,600 to 3,600. Fishing workers rose from 1,120 to 1,440, an increase of 320, even though their share fell. Canning workers rose from 80 to 1,260, an increase of 1,180.
Step 3, use the sources as viewpoints. Source A suggests that around 1902 the author saw boats as central to home life. Source B suggests that in 1951 the author saw canning as dominant and described change as a loss. Both are opinions, so they support the table but do not replace it.
Step 4, the sentence: “The table shows that fishing’s share of Harbourtown’s jobs fell from 70% to 40% between 1900 and 1950, while canning’s rose from 5% to 35%. Even so, the number of fishing workers increased from 1,120 to 1,440, so fishing declined in share but not in size.”
That is documented change: two dates, one dimension, matched measures and a precise statement.
The mistake to watch for
A common slip is to confuse a share with a number, or to use opinion as proof.
Mistaken answer: “Fishing declined in Harbourtown because it fell from 70% to 40%, and Source B says the old way of life is fading.”
The student treated a falling share as fewer fishers, and used a viewpoint as if it proved the change.
The fix is to check the count: fishing workers actually rose. Then say what each piece shows. The table shows a change in share, and Source B shows how one author felt about it.
Check yourself
1. Harbourtown’s population was 4,000 in 1900 and 9,000 in 1950 (invented). By how much, and by what percentage, did it grow?
Show answer
Increase = 9,000 − 4,000 = 5,000. Percentage = 5,000 ÷ 4,000 × 100 = 125%.
2. Source C (invented), 1930: “The harbour is busier than anyone remembers.” Does this prove fishing grew by 1930?
Show answer
No. It is one author’s viewpoint at one date. It suggests the author saw more activity, but it needs a record, such as a count of boats or workers, to establish growth.
3. In 1950, 40% of 3,600 workers were in fishing. How many is that?
Show answer
40% of 3,600 = 0.4 × 3,600 = 1,440 workers.
Where this leads next
Change is only half the picture, so the next lesson teaches you to identify continuity without overlooking variation. You can also look back at the module’s source and evidence skills.
Matching evidence from two dates is a habit that gets sharper with feedback. A teacher on online one-to-one History tuition can check your evidence choices against your own course requirements.