One way to link texts is through the purpose they are aiming to achieve and the form they are using.
Form is the type of text, for example:
It’s also useful to think about whether the form is for a public or private audience. For example, a letter is usually for a private audience while a news article is usually for a public audience. This will affect the purpose of the text and the language choices made by the writer.
Purpose is what the writer is trying to achieve, for example:
It’s very important to remember that often a writer will have more than one purpose. For example, a fashion blog may want to entertain, as well as inform and advise.
When comparing texts, consider what they have in common AND what is different about them.
If they have the same main purpose:
If they have a different purpose but the same subject:
Look at these headlines, from The Mirror and The Telegraph, from articles reporting the same story. They have the same main purpose – to inform people about the landing of a space probe on a comet.
Rock starThe Mirror
European Space Agency's Rosetta spacecraft lands probe on cometThe Telegraph