GoalExplain how a search engine and a digital map use algorithms, and why keywords matter.
New words
search engine · a program that helps you find information on the internetkeyword · an important word you type to searchresult · a page or fact the search engine showsrelevant · fits what you are looking for
Explanation
A search engine is a program that helps you find information on the internet. When you type keywords, it follows an algorithm: it looks through the information it keeps, picks the results that match your words best, and puts the most relevant ones first. A digital map does something similar: you tell it where you start and where you want to go, and it uses its data about the roads to give you directions. Because the engine follows your words exactly, choose your keywords carefully. “Animal” gives a huge mixed list, but “how many days can a camel live without water” is far more exact. Use search engines with a teacher or a grown-up, and check the sources you find.
I type keywords→The algorithm looks through its information→It picks the best matches→It shows a list→I check the sources
Worked examples
Vague keywords
Better keywords
animal
how many days can a camel live without water
ball
rules of football for children
Vague words give mixed lists; exact words give closer results.
Karim tells a digital map he starts at the school and wants to reach the library. The map uses its data about roads to give him the steps: go straight, then turn left.
Hana types “mouse” and sees pictures of an animal and of a computer part. She adds the word “computer” and gets only the computer part. The extra word made the search more exact.
Class activity
A human search engine. One child is the “search engine” with 12 picture cards of animals (some live in water, some in the desert). The others ask: “big animals that live in water”. The engine finds the matching cards and puts the best match first. Then ask just “animal”: what happens? Talk about why exact words help.
Practice
1
What does a search engine do when you type your keywords?
It follows an algorithm to find the results that match your words best and shows the most relevant first.
2
Which keywords are better? A: “bird” B: “what does a sparrow eat”
B, because it is more exact.
3
How does a digital map give directions?
It uses its data about roads and an algorithm to choose the steps.
4
Put in order: A the engine shows a list, B I type my keywords, C I check the sources, D the engine picks the best matches.
