8CS1 - 8.4.5 - Tightening the web

• Computing
• Lower Secondary (Key Stage 3)

Recap: What does this HTML tag allow us to do to a web page:

<img src …….>

8.4.5 - Tightening the web

Year 8 – Developing for the Web

Mr Hughes' expectations

It’s ok to be wrong.

Cold calling, everybody needs an answer.

Listen when others are speaking.

Work on teams. Today’s lesson on the slides.

No shouting out – hands up for any questions.

Don't wait for me to tell you what to do with the tasks.

Learning Objectives

• Use search engine terms effectively
  
• Discuss how the choice of search terms affects the information you find
  
• create hyperlinks to navigate between multiple web pages

Name 3 parts of a search engine

How does a search engine work?

Think. Pair. Share

Fish: Live in water and are cold-blooded.

Mammals: Can be found in water or on land are warm-blooded and their young drink milk.

Amphibians: Can be found in water or on land and are cold-blooded.

Birds: Have feathers and can fly.

Reptiles: Can be found on land and are cold-blooded.

Arthropods: Have more than four legs and are old-blooded.

Overlapping groups

“Which animals can live in water?”

What would we type into google to narrow our search results to just display birds?

Which animals have feathers?

Would be a great question to ask Google

If you want fewer answers, you can include more details to narrow your search results

What would you add to this question to have amphibians and mammals as the answer?

“Which animals can live in water ………… can live on land?”

Narrowing results

1. AND
2. OR
3. NOT

Sometimes you may want a broader range of answers, so you would specify two separate parts to the questions.

What word could you add to a question to have both mammals and arthropods as the answer?

“Which animals drink milk as babies ………… have more than four legs?”

Combining groups

1. AND
2. OR
3. NOT

You can ask questions that eliminate groups that you don't want as part of the answer.

What word could you add to a question to only get arthropods as the answer?

“Which animals do ………… have fewer than five legs?”

Excluding groups

1. AND
2. OR
3. NOT

If you asked: “Which animals have wings AND are NOT warm-blooded?”

The answer would be:

Combining parameters

1. Reptiles
2. Arthropods
3. Mammals
4. Birds

Birds, arthropods (ladybirds) and mammals (bats) have wings but only arthropods have cold blood.

Excluding groups

You can ask questions that eliminate groups that you don’t want as part of the answer.

What word could you add to a question to only get arthropods as the answer?

“Which animals do ………… have fewer than 5 legs?”

1. AND
2. OR
3. NOT

Search engine index

Search engines like Google use software called crawlers. They catalogue a huge number of web pages each day.

Depending on what we search for, there could be billions of web pages that match each possible keyword.

In the same way that you narrowed down the results of animal searches, you can narrow the number of results found by search engines.

Default searches

The default of a search engine is to return results using the AND operator.

This requires all keywords to be present on any place on the web page returned as part of the search.

This search engine has found 58.6 million results for Edinburgh AND castle.

Controlling searches

Search engines provide operators to help control a search more carefully:

Controlling a search

You are going to investigate the impact these operators have on the number of results returned by a search engine.

Once you have all finished, we will compare the number of results you got and see who has used search terms and operators to the best effect.

I Do

Alan Turing and Grace Hopper Google searches using only the keywords "turing" and "hopper'

turing hopper - how many results?

We Do

Alan Turing and Grace Hopper Google searches using only the keywords "turing" and "hopper'

Workbook on teams

turing and hopper - how many results?

turing not how many results?

"turing hopper" - how many results?

We Do

• Open google in Chrome
• Type in "turing" into the browser - note the amount of results
• Type in 'hopper" - note the amount of results

turing - how many results?

hopper - how many results?

We Do

• Type in "turing -hopper" How many did we get?

turing -hopper - how many results?

You DO

Task 1 on todays teams (8.4.5 - tightening the web)

Top tips: Search parameters are 

OR

- (NOT)

" " (Phrase

turing -hopper - how many results?

Many web pages

So far we have only considered single, standalone web pages.

We know from experience that many web pages are connected together to form websites.

We browse between pages of a site using hyperlinks.

Hyperlinks in HTML

Web pages are modified using a tag that marks text or images as ‘clickable’ to link through to a different page.

<a href="RPi4.htm">

  <img src="TopView.jpg">

</a>

Image file “TopView.jpg” hyperlinked to HTML file RPi4.htm.

<a href="RPi4.htm">Find out more</a>

Text “Find out more” on page hyperlinked to HTML file RPi4.htm.

Note that the target HTML file needs to be in the same folder as the starting page as you saw in lesson 2.

Building a high quality web site

Using the webpage from last lesson, open in notepad++ and the browser.

1) Create a link in the HTML above the closing body tag

2) Create a new file in Notepad++ called search_engines.html and add 3 <p></p> tags with new content on the HTML which summarises how to use different search parameters effectively, specifically:

• How OR works
• How NOT works (the - symbol)
• How phrase searches work (using “” marks)

 

Take a screenshot of your webpage and upload it here (WIN + SHIFT + S, save your screenshot to your documents and upload below)

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