ACT Reading: Evaluate Source Credibility and Authority—Distinguish Reliable from Unreliable Sources

Credibility factors: (1) Author expertise: Does the author have relevant qualifications? A climate scientist writing about climate change is credible; a celebrity is not (unless they've studied the topic). (2) Evidence quality: Does the author cite peer-reviewed studies, named experts, or primary sources? Or do they claim "everyone knows" without proof? (3) Bias: Does the author have financial or ideological interest in the outcome? A tobacco company's study on smoking is suspect; a university's independent study is more credible. (4) Recency: Is the information current? For fast-moving fields (medicine, technology), old sources are less credible. (5) Institutional backing: Universities, government agencies, and peer-reviewed journals have editorial processes; random blogs don't. On the ACT, questions ask: "Which source is most credible?" or "What does the author's background suggest about credibility?" Recognizing these factors helps you evaluate arguments. Credible sources provide evidence, acknowledge limitations, and avoid emotionally manipulative language.

Why evaluation matters: In an age of misinformation, distinguishing credible sources from unreliable ones is critical reading skill.

Red flag 1: Appeals to emotion without evidence. "Everyone agrees..." or "Obviously..." without data suggests weak evidence. Red flag 2: Dismissing opposing views without engaging them. Credible authors acknowledge counterarguments. Red flag 3: Cherry-picking data. Presenting only statistics supporting one view while ignoring contradictory data. Red flag 4: Unnamed sources or vague expertise. "Sources say..." or "Scientists believe..." without naming them is suspicious. Red flag 5: Extreme or sensational language. "Destroy," "catastrophic," "revolutionary" without nuance signal bias. Red flag 6: No citations or references. Where did this information come from? Red flag 7: Conflict of interest not disclosed. A pharmaceutical company studying their own drug without mentioning financial interest is suspect. Red flag 8: Ad hominem attacks. Attacking the person instead of addressing their argument. The more red flags, the less credible the source.

Checklist: (1) Who is the author? What are their credentials? (2) What evidence do they provide? Is it verifiable? (3) Do they acknowledge limitations or opposing views? (4) Is there a hidden agenda or financial interest? (5) Does the language feel emotionally manipulative or balanced?

Source 1: A peer-reviewed journal article on climate change by a researcher at MIT with citations to 100+ studies. Credibility: Very high. Reason: Institutional backing, expert author, extensive peer review and citations. Source 2: A blog post claiming vaccines cause autism, citing no sources and dismissing the author's critics. Credibility: Very low. Reason: No evidence, dismissive tone, contradiction of scientific consensus, no author credentials mentioned. Source 3: A government health agency report on medication side effects, updated annually with data from clinical trials. Credibility: High. Reason: Institutional authority, evidence-based, current, transparent process. Source 4: A social media post saying "Everyone knows coffee is bad for you" with an emotional testimonial but no studies. Credibility: Low. Reason: No evidence, appeal to emotion, unnamed sources. Source 5: A book by a nutrition researcher published by a university press, acknowledging research gaps and funding sources. Credibility: High. Reason: Expert author, institutional backing, transparency about limitations. For each source, list credibility factors and red flags present or absent.

Daily drill: Read different types of sources (journal, blog, news, social media). Evaluate each for credibility. List factors supporting or undermining authority. Over one week, notice patterns in credible vs. unreliable sourcing.

Credibility questions usually ask you to identify the most reliable source or assess an author's bias. These test higher-order thinking: Can you distinguish reliable from unreliable? Can you recognize bias and financial interests? Students who evaluate credibility score 1-2 points higher on argument and evidence questions because they understand that not all sources are equal—some are backed by expertise and rigor, others by emotion and bias.

This week, practice evaluating sources. For every passage, assess the author's credibility and note bias. By test day, you'll read with a critical eye and answer source evaluation questions confidently.