The results stunned Google's Uber Tech Lead for Search Quality and User Happiness, Dan Russell.

"I interviewed a bus driver who was searching for a transportation rule for a test," Mr Russell told the New Scientist magazine in an interview published yesterday.

"She was scrolling line-by-line through a 100-page web document, so I asked her why she didn't use 'control+F' to search by keyword. It turns out she didn't know about this absolutely basic browser function."

(NB: Where the CTRL-F "find" box appears on your computer screen depends on which browser you use - for instance, a box will appear top left of your computer screen if you use Internet Explorer, bottom left if you use Firefox, top right if you use Chrome.)

So how can 90 per cent of users not be aware of this simple but useful shortcut?

Mark Pesce, a futurist and honorary associate in digital cultures at the University of Sydney, said it was all about the lack of education.

"I really think there's been no effort at any level - whether it's in a company or school or even nationally - to teach people.

"I think we just all assume that we all know it, but no one actually does."

Mr Pesce said the responsibility to educate the public on such tools could fall on librarians, who use search tools as part of their job.

He told public librarians at their annual meeting this month they were "going to be principally responsible for training a nation that's about to get a National Broadband Network, [and] that has no idea how to use it".

"The problem exists because people are habitually trained by what they always do on computers and they don't go beyond that.

"Librarians shouldn't have to educate everyone. They should simply be capable of training people who can then train other people."

Mr Pesce also criticised the search giant for not educating its users on how to use its tools.

"I think it's a little rich for Google to be talking about what users do and do not do because Google offers no training," he said.

"Doing these things is not hard. It just takes effort [and] dedication to educating your user base."

So what other keyboard shortcuts should computer users know about? (For Windows OS. Swap CTRL for Apple's Command key):

CTRL-F or F3: to find a word or words on a page

CTRL-C: to copy text

CTRL-V: to paste text

CTRL-Z: to undo a command

SHIFT-CTRL-Z: to redo the command above

CTRL-S: to save

CTRL-B: to bold text

CTRL-I: to italicise text

CTRL-U: to underline text

CTRL-X: to cut text

CTRL-A: to select all

CTRL-O: to open a file

CTRL-P: to print

CTRL- "-" or "+": to reduce or increase font size on a webpage

And more ...

CTRL-H: history

WIN-L: to lock your desktop (Windows)

WIN-D: to show your desktop (Windows)

F5: to refresh a page

ALT-Print Screen: to capture a screenshot of a window on your desktop

ALT-Home: to go to your browser's homepage

CTRL-T: to open a new tab in your web browser

CTRL-TAB: to scroll through the tabs on your web browser

CTRL-W: to close a window on your web browser

CTRL-Home: to go to the start of a sentence

CTRL-End: to go to the start of a sentence

CTRL-"?" or "?": to move to the previous or next word

CTRL-SHIFT-"?" or "?": to select the previous or next word

Further reading: 100 keyboard shortcuts (Windows)Mac shortcutsLinux shortcuts

View the story "Keyboard shortcuts - what do you know?" on Storify]