Reading: Advanced Textual Analysis
C1 Lesson 3: Evaluating Evidence, Sources, and Author Credibility
Questioning the Information
A truly advanced reader does not just analyze an author's argument; they critically evaluate the evidence1 that the argument is built upon. In an age of misinformation, it is essential to question where information comes from.
Today, we will learn how to assess the quality of evidence by examining the credibility2 of the source3 and the author. This means asking, "Can I trust this information, and why?"
Part 1: A Critical Reader's Checklist for Evaluating Sources
When you encounter a new piece of information, use these five questions to judge its credibility:
- Currency: Is the information up-to-date? (For science and technology, recent information is crucial).
- Relevance: Does the evidence directly support the author's specific claim?
- Authority4: Who wrote this? Are they an expert in this field? Is the publication reputable?
- Accuracy: Can the information be verified from other reliable sources? Are there citations?
- Purpose: Why was this text created? Is the purpose to inform objectively, or to persuade you with a potential bias5?
Part 2: Analyzing Two Sources on the Same Topic
Let's evaluate two different texts about the health benefits of Kampot sea salt.
Text 1: An Unreliable Source (Blog Post)
Title: The Miraculous Healing Power of Kampot Salt!
Source: KampotWellnessSecrets.com, by "NatureLover25"
Did you know that the amazing salt from our beautiful sea can cure almost any illness? I read a comment online that said a man cured his high blood pressure just by drinking salt water! My aunt also says she feels much more energetic after switching to local sea salt. This natural product is clearly a miracle cure that doctors don't want you to know about.
Evaluation: This source is NOT CREDIBLE. The author is anonymous, the evidence is anecdotal ("a comment online," "my aunt"), the claims are extreme ("miracle cure"), and the purpose is likely to persuade through emotion, not facts.
Text 2: A Credible Source (Academic Journal)
Title: Mineral Composition of Unrefined Sea Salt from Kampot
Source: Cambodian Journal of Science & Health, by Dr. Chea Sokha, PhD.
A study published on June 10, 2025, analyzed the mineral content of unrefined sea salt from Kampot province. The analysis revealed that, in addition to sodium chloride, the salt contains trace amounts of minerals such as magnesium and potassium. While these minerals are vital for human health, the report cautions that the quantities are not sufficient to provide a significant therapeutic effect from typical consumption. The report concludes that unrefined sea salt can be part of a balanced diet.
Evaluation: This source is CREDIBLE. The author has clear authority (PhD), the publication is academic, the claims are specific and cautious ("trace amounts," "not significant"), and the purpose is to inform objectively based on scientific analysis.
Your Turn! Evaluate the Evidence.
Practice Quiz
Read the following claim and evaluate the evidence.
Claim: "A new post on a Facebook page called 'Ancient Secret Health' claims that standing on one leg for 10 minutes every day can cure cancer. The evidence provided is a testimonial from one user who says, 'My friend did this and his cancer disappeared! It really works!'"
Why is this claim and its evidence highly unreliable?
- A. The claim is published in a major medical journal.
- B. The source is not an expert, the evidence is a single unverified story (anecdotal), and the claim is extreme and unscientific.
- C. The person writing the post has a lot of followers on Facebook.
Answer: B. The source lacks authority, the evidence is insufficient and not credible, and the purpose is to persuade based on a miracle claim, not to inform with facts.
Vocabulary Glossary
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Evaluate Evidence (verb phrase)
ភាសាខ្មែរ: ការវាយតម្លៃភស្តុតាង
To critically judge the quality, relevance, and reliability of information used to support an argument. ↩ back to text -
Credibility (noun)
ភាសាខ្មែរ: ความน่าเชื่อถือ
The quality of being able to be believed and trusted. ↩ back to text -
Source (noun)
ភាសាខ្មែរ: ប្រភព
The person, publication, or document that information comes from. ↩ back to text -
Authority (noun)
ភាសាខ្មែរ: អ្នកជំនាញ
The recognized expertise or knowledge that makes a source trustworthy. ↩ back to text -
Bias (noun)
ភាសាខ្មែរ: ភាពលំអៀង
A prejudice that unfairly favors one side and prevents objective consideration of an issue. ↩ back to text
Homework Task
Be a Source Detective!
Find an English news article or blog post online that makes a specific claim about science, health, or technology.
- Analyze the source. Who is the author and what is the publication? Do they have authority on this topic?
- What evidence does the author provide to support their claim? Do they cite studies, experts, or data?
- Based on your analysis using the checklist from the lesson, write a short paragraph explaining whether you think the source is credible or not, and why.