Internet Browsing & Search

What this lesson covers

Internet Browsing & Search is a 10-part Class 6 Computer Science lesson. Each part makes one point and then hands over to the next, so it can be read in a sitting or picked up again at the part you stopped on. It defines the idea in plain words before using it, works through an example step by step, breaks the topic into its parts and compares them, shows where it is used outside the textbook, names the mistakes that cost marks in an exam, ends with a recap of what to remember.

How it begins

A search engine does not search the internet when you type. That would take far too long. Instead, programs called crawlers visit pages continuously and build an index, a huge catalogue of which words appear where. When you search, it looks in that index and ranks the results by how relevant and trustworthy it judges each page to be. Which means results are ranked by an opinion (a program's opinion) not by truth.

The 10 parts

1. How a search engine works
2. Reading a URL
3. Searching precisely
4. Evaluating a source
5. How results get ranked
6. Spotting an unreliable page
7. Researching properly
8. Where it usually goes wrong
9. What to remember
10. Watch one worked through