Teacher shows the Powerpoint presentation Futureproofing data: Futureproofing in the past (slides 1–10 only), using the presentation notes accompanying each slide to supply background that is of interest for each.
After viewing, discuss the following with students:
Comment to students:
Show students the Powerpoint presentation Futureproofing data: Futureproofing in the past (slides 11-20), and use the teacher notes accompanying each slide to supply background for each.
If you have access to the actual storage devices and/or media, then display them also.
If enough physical examples exist then have a “Hardware Expo”. Broaden the experience beyond storage devices by including input, output and processing devices as well. Cut out the numbers provided on the following worksheet to identify each item. Cut out separate strips and issue as many as desired to each student. Students research and complete as much as possible of the worksheet (Hardware Expo) provided. If wished, they can then be required to present one item to the class.
If enough physical examples exist then have a 'Hardware expo'. Students research and complete as much as possible of the worksheet (Hardware Expo) provided.
Discuss with the class the history of the evolution of data storage over the years, and your personal experience of it.
Many of us have had experience of accidentally deleting a file. Explain to students that, if the file is important enough to us, it is sometimes possible for it to be retrieved, as deletion on a hard drive does not erase the data immediately, but merely removes the item indexing it. Until it is overwritten, the data is still there. This is often used by law enforcement agencies to retrieve incriminating digital evidence.
Read the following to the class:
'A destructive scam email that infects computers and holds them hostage has successfully targeted at least 10,000 Australians since it was detected this week. The email, purporting to be from energy company AGL, sends a fake bill and prompts the recipient to click on a link to download a copy. It then saves a .zip file on the computer which, when extracted, locks the machine down using malware known as "ransomware". The recipient is prompted to pay $A880 to unlock it. A senior analyst at a global cybersecurity firm said once the file has downloaded ransomware the only way to get rid of it is to restore from a backup or to wipe the computer and start over again.'
Source: 'Thousands targeted by "ransomware" email scam which copies AGL Energy bills' Georgina Mitchell - accessed June 3 2016
This example of a scam email is known as a Trojan horse (named after the ancient Greek story of the wooden horse that was used to help Greek troops invade the city of Troy). It is a form of malware, where a malicious program, pretending to be something innocent, tricks a user into executing it.
Explain that viruses can corrupt data, delete files altogether, erase a hard disk and send infected files to contacts in your address book. Tell students: Computer viruses can spread when you:
Discuss data loss as a result of malware or viruses.
Discuss with the class what precautions can be taken to protect computers against data loss by viruses and malware.
Show the students the PowerPoint presentation Futureproofing data: Data storage research (slide 21).
Students in eight groups research each of the media listed in this slide, and then complete the missing information.
A research summary is provided here for your reference:
|Storage medium||Year launched||Capacity||Type of medium||Estimated life expectancy|
|Cassette tapes||1962||400 KB||magnetic||10–20 years but can wear out with use|
|Floppy disks||1971||1.44 MB||magnetic||2–15 years|
|Zip disks||1994||100 MB/750 MB||magnetic||2–10 years but can wear out with use|
|CD-R/DVD-R||1990/1997||700 MB||optical||5–25 years|
|Hard disk drive||1960s||3.75 MB (now 10 TB)||magnetic||3–5 years|
|USB Flash||2000||8 MB||Solid state||10 years or 100,000 cycles|
|SSD Solid State Flash drive||1989||250 MB–1 TB||Solid state||Various ratings are given: 10 years or 100,000 cycles or 20 GB writes per day for 3 years|
|Cloud storage||1960s||?||Magnetic, hard drives on distributed servers|
Lucky dip research
Print one copy of the PDF resource provided: Lucky dip scenarios.
These 'data dilemmas' should be cut into individual strips and placed in a lucky dip.
These scenarios include retrieving deleted files and data loss as a result of viruses or malware.
Students (pairs are suggested) select one scenario, developing their response to the scenario given.
Allow 10–15 minutes, after which pairs read their scenario aloud then informally report their response back to the class.
Ask students to discuss the following: