Evaluation explains how the strengths and limitations of evidence and sources affect the research and argument. High marks require several developed evaluative points, not a list of generic comments.

Learning Objectives

Evidence And Source Are Related But Different

The source is where information comes from, such as a research article, government report, interview or company webpage. Evidence is the information used to support a claim, such as a statistic, observation, quotation or research finding. A credible organisation can publish weak evidence, and a source with an interest in the issue can still provide useful data. Evaluation must therefore focus on the particular material being used.

The purpose is not to prove that every source is unreliable. It is to judge what the evidence can and cannot support.

Key Evaluation Criteria

• Authority: Does the author or organisation have relevant expertise or direct knowledge?
• Method: How was the evidence collected, measured or selected?
• Sample: Is it large enough, representative and appropriate for the claim?
• Currency: Is the evidence recent enough for the issue, and is the underlying data current?
• Relevance: Does it answer the research question and fit the location or group being discussed?
• Corroboration: Is the claim supported by independent evidence?
• Transparency: Are methods, definitions, limitations and funding explained?
• Purpose and interest: Is the source informing, selling, campaigning or defending a policy?
• Reasoning: Does the conclusion follow from the evidence, or are assumptions and generalisations present?

Developed Evaluation

A basic comment says, “This source may be biased.” A developed comment identifies the reason and consequence: “The report was funded by companies that benefit from the policy, creating a possible vested interest. Its cost estimates are still useful because the calculation method is published, but the predicted benefits should be checked against independent research before they are used to justify national adoption.”

Evaluating Quantitative Evidence

Check definitions, units, time period, sample selection, missing data and whether averages hide variation. Relative changes can sound dramatic when the starting number is small, while absolute figures may hide population differences. Correlation does not automatically establish causation. A prediction depends on assumptions that should be identified.

For surveys, consider wording, response rate and whether respondents were selected randomly. For experiments, consider controls, replication and whether findings can be applied beyond the study setting. For national data, consider whether collection methods are comparable across countries.

Evaluating Qualitative Evidence

Interviews, testimonies and case studies provide depth, context and lived experience. Their value may be high for understanding how an issue affects a group, even when they cannot estimate prevalence. Consider how participants were selected, whether questions were leading, whether translation affected meaning and whether the account can be corroborated.

Do not dismiss testimony simply because it is subjective. Instead, use it for claims it can support, such as experience or perspective, and avoid treating it as proof of the scale of a global trend.

Evaluating Stakeholder Sources

Stakeholder sources are essential for understanding perspectives. Their interests do not make them useless. A company may be the best source for its own policy, an advocacy group for its campaign priorities, and a government for official targets. However, their claims about effectiveness or wider impact need independent checking.

Bias means a systematic tendency in selection, interpretation or presentation. It should be demonstrated through evidence, language, omissions, funding or method rather than asserted because the writer disagrees with the source.

Place Evaluation Where It Matters

Evaluation can be integrated after evidence is introduced: present the claim, cite the source, explain its strength or limitation and show how this affects the paragraph’s judgement. A later paragraph may compare several sources and explain why one carries more weight. The report should include enough developed evaluation to show sustained critical research.

Common Mistakes To Avoid

• Calling a source reliable only because it is a government, university or international organisation.
• Calling a source biased without explaining evidence of bias or its effect.
• Using the same generic evaluation for every source.
• Evaluating the website design instead of the evidence and method.
• Mentioning sample size without considering representativeness.
• Rejecting older sources automatically when they provide important historical or long-term evidence.
• Evaluating sources in a separate list with no connection to claims in the report.

Quick Practice