Media & Information Literacy Grade 6: How Search Engines Work

Grade 6 Media & Information Literacy Study Guide: How Search Engines Work

1. The Driving Question

"If you type ‘why do cats purr’ into Google, how does it instantly show you a list of answers—including some that seem perfect and others that don’t make sense at all? And why does the same search on Bing or DuckDuckGo give you different results? Are search engines just guessing, or is there a hidden system deciding what you see?"

2. The Core Idea — Built, Not Listed

Imagine you’re in a giant library where every book is piled on the floor in no particular order. You need to find one specific fact—say, the year the first video game was invented. Without a librarian or a catalog, you’d have to open every book until you found it. That’s how the internet used to work before search engines.

A search engine is like a team of hyper-organized librarians who:
1. Crawl the internet (like sending robots to flip through every book in the library).
2. Index what they find (like writing down every word in every book and where it appears).
3. Rank the results (like deciding which books are most likely to have the best answer to your question).

When you type a search, the engine doesn’t search the internet live—it searches its index (a giant, constantly updated list of words and pages) and then uses secret rules (called algorithms) to decide which pages to show you first. The rules aren’t random: they’re based on things like how many other pages link to a site, how often your search words appear, and even how fast the page loads.

Key Vocabulary: - Algorithm – A step-by-step set of rules a computer follows to solve a problem. Example: The recipe your phone uses to suggest TikTok videos is an algorithm—it picks videos based on what you’ve watched before, not just random ones. Note: In high school, you’ll learn algorithms can be biased if the rules favor certain groups over others.

• Crawling – When a search engine’s bots (called spiders) scan the internet to find and read web pages. Example: If you post a blog about your soccer team, Google’s spiders will eventually "crawl" it and add it to their index—like a librarian adding a new book to the shelves.

• Index – A massive database where search engines store information about web pages (like a library catalog). Example: If you search "how to make slime," the engine checks its index for pages with those words, not the whole internet.

• Ranking – The process of sorting search results by relevance and quality. Example: If you search "best pizza near me," the top results are ranked based on reviews, location, and how many other sites link to them—not just because the word "pizza" appears a lot.

3. Assessment Translation

How this appears on state tests (Grade 6): - Multiple Choice: Questions about how search engines work (e.g., "What does a search engine’s ‘index’ do?") with distractors like: - "It searches the internet in real time." (Wrong—it searches the index, not the live web.) - "It blocks harmful websites." (Wrong—filtering is separate from indexing.) - Short Answer: "Explain why two people searching the same phrase might get different results." (Proficient answers mention location, search history, or algorithm differences.) - Evidence-Based Writing: "Read this article about search engine bias. Use evidence to explain how algorithms can influence what information people see."

What a proficient response looks like: Prompt: "Why might a search for ‘climate change’ show different results on Google than on DuckDuckGo?" Proficient Answer: "Google and DuckDuckGo use different algorithms to rank results. Google’s algorithm might prioritize pages from government sites like NASA or NOAA because they’re trusted sources, while DuckDuckGo might show more news articles or blogs. Also, Google personalizes results based on your search history, but DuckDuckGo doesn’t track users, so its results are the same for everyone. Both engines crawl and index the same internet, but they decide what to show first in different ways."

What teachers look for: - Developing: Vague answers ("They’re different companies") or mixing up terms ("Google crawls faster"). - Proficient: Explains how algorithms differ (personalization, ranking rules) and gives an example. - Advanced: Notes that algorithms can be biased (e.g., favoring certain viewpoints) or mentions specific ranking factors (like backlinks).

4. Mistake Taxonomy

Mistake 1: Confusing "crawling" with "searching" Prompt: "What happens when you type a question into a search engine?" Common Wrong Answer: "The search engine goes to every website to find the answer." Why It Loses Credit: This describes crawling, which happens before you search. The engine searches its index, not the live web. Correct Approach:
1. The engine checks its index (like a library catalog).
2. It uses algorithms to rank pages by relevance.
3. It shows you the top results in seconds.

Mistake 2: Thinking all search engines give the same results Prompt: "Why might your friend see different results than you for the same search?" Common Wrong Answer: "Because they used a different search engine." (Incomplete—doesn’t explain why the results differ.) Why It Loses Credit: The answer doesn’t mention personalization (search history, location) or algorithm differences. Correct Approach: - Google personalizes results based on your past searches and location. - DuckDuckGo doesn’t track users, so its results are the same for everyone. - Some engines prioritize ads or certain types of sites (e.g., Wikipedia vs. news articles).

Mistake 3: Assuming the first result is always the "best" Prompt: "How do search engines decide which results to show first?" Common Wrong Answer: "They show the most popular websites." (Too vague—doesn’t explain how popularity is measured.) Why It Loses Credit: Doesn’t mention specific ranking factors like backlinks (other sites linking to a page) or keywords. Correct Approach: - Algorithms look for keywords (how often your search terms appear). - They check backlinks (how many other sites link to a page). - They consider page quality (how fast it loads, if it’s mobile-friendly). - Some engines also use personalization (your search history).

5. Connection Layer

• Within Media Literacy: How search engines work-how social media feeds are curated. Why it matters: Both use algorithms to decide what you see, but social media prioritizes engagement (likes, shares) while search engines prioritize relevance. Understanding one helps you question the other.

• Across Subjects: Search engine algorithms-scientific peer review. Why it matters: In science, experts decide which research is trustworthy by checking citations (like backlinks). Search engines do something similar—pages with more links from other sites rank higher, just like studies cited by other scientists.

• Outside School: Search engine ranking-how Yelp or Amazon sorts reviews. Why it matters: Yelp doesn’t show you the newest reviews first—it ranks them by "usefulness" (like search engines rank by relevance). Now you’ll notice when a site is pushing certain results over others.

6. The Stretch Question

"If a search engine’s algorithm is just a set of rules, could it ever be ‘wrong’? For example, if you search ‘Are vaccines safe?’ and the top results are all anti-vaccine websites, is that the algorithm’s fault—or is it just showing what people click on the most?"

Pointer Toward the Answer: Algorithms aren’t neutral—they reflect the biases of the people who design them and the data they’re trained on. If most people click on anti-vaccine sites for that search, the algorithm might rank them higher, even if they’re not the most accurate. This is why media literacy matters: the "top result" isn’t always the best result. In college, you’ll study how algorithms can reinforce stereotypes or spread misinformation if they’re not carefully monitored.