To compare supporting evidence fairly, use the same checks on every source and judge the evidence, not the actor or the choice it supports. Your conclusion may be that one claim is better supported on the information given, which is different from saying one side is right.
This lesson completes the skills in comparing perspectives and follows explaining why two sources answer different questions.
What are the same-checks?
Use four checks on each piece of evidence.
- Type: a survey, a measurement, a forecast, a quotation, a case study?
- Method and openness: is it explained how the evidence was gathered?
- Coverage: how many cases, which group, what period?
- Fit: does the evidence directly support the claim it is used for?
For source reliability in general, revisit sources and credibility as needed. Here the focus is the evidence offered for each claim.
Why avoid ranking actors and choices?
Ranking an actor (“the council is more honest than the company”) needs evidence about character, which the sources rarely supply. Ranking a choice (“the marina is the better option”) is a political judgement that depends on values as well as evidence.
What you can fairly rank is how well a claim is supported on the information provided. Keep that wording in your answer.
Worked example
All sources are invented for practice.
Claim 1 (Source A): the marina would bring noise problems. Evidence: 74 of 120 surveyed households (62%) said they expected noise. The survey method is described, but the answers are expectations.
Claim 2 (Source D): the marina would support 40 service jobs. Evidence: an estimate based on one other marina. The source does not say how similar that marina is.
| Check | Claim 1 | Claim 2 |
|---|---|---|
| Type | Survey of expectations | Estimate from one comparison |
| Method and openness | Method described | Comparison not explained |
| Coverage | 120 households | One other site |
| Fit | Shows expectations, not measured noise | Shows a comparison, not a local count |
Fair conclusion: “Both claims rest on limited evidence. Claim 1 shows what a group of residents expect, while Claim 2 gives an estimate from a single comparison. Neither source measures the outcome directly, so each claim is only partly supported on the information given.”
The mistake to watch for
Mistaken conclusion: “The residents’ evidence is better because they live there, so the marina should not be built.”
This ranks the people (living there) and then jumps to a policy choice. The evidence table showed expectations, not measured noise. The correction is to compare the two pieces of evidence on the four checks and stop at “partly supported”, without recommending a political choice.
Check yourself
1. Which of these is a judgement about evidence: (a) “The agency cannot be trusted”, (b) “The report does not explain how it counted visitors”?
Show answer
(b). It names a gap in method. (a) is a judgement about the actor with no evidence behind it.
2. Source X: a measured noise reading taken at 10 houses over a week. Source Y: a quotation from a resident saying it was noisy. Compare their coverage and fit.
Show answer
X covers 10 houses over a period and measures noise directly. Y covers one person’s experience. X fits a claim about noise levels more directly. Y still shows how one person experienced it.
3. Rewrite so it ranks evidence, not a choice: “The tax is the right policy because the study agrees with it.”
Show answer
“The study supports the claim that the tax reduced waste, using data from 6 towns over 2 years. This is stronger support for that claim than one town’s anecdote, though it does not settle whether the tax is the right policy.” The conclusion stays about the evidence.
Where this leads next
You now have four skills: describe, separate, compare questions, weigh evidence. Try them together in the comparing perspectives practice set.
If you want someone to check that your conclusions stay on the evidence, our teachers can read your drafts with you in online one-to-one Global Perspectives tuition. They support your own reasoning and do not write your assessed work.