Paper 1 2015 Question 4 Key

(a) (i) Outline one difference between streaming and downloading videos. [2]
Answers may include:

 streaming video is content sent in compressed form over the internet and displayed by the viewer in real time / downloaded videos are stored on a local device and played later
 streaming video can start to be played as soon as sufficient data arrives / downloaded videos must finish downloading before they can be played
 streaming video requires a network connection to be maintained throughout the playing / downloaded video can be stored for offline playback
 streaming videos may pause or stutter if the bandwidth/data transfer rate is too low / downloaded videos are more likely to play without interruption from the hard disk
 Download videos occupy storage space on the local device / streaming videos are only stored temporarily while they are being played

Award [1] for identifying a difference for either streaming or downloading videos with an implied reference to the other.
Award up to a maximum of [2] for an outline of a difference between streaming and downloading videos that explicitly refers to both methods of watching videos.

(ii) Define the term “bandwidth”. [2]

Answers may include:
 bandwidth is often used as a synonym for data transfer rate
 amount of data that can be transmitted in a given amount of time
 expressed in bits per second (bit/s) (accept kb/Mb/Gb, accept answers expressed in Bytes).

Award [1] for a basic comment about bandwidth with [1] for each additional comment up to a maximum of [2].

(iii) The science teacher wants to show to the class a video about polar bears and how they survive living near the north pole. The size of this video is 3.2 gigabytes (GB) and is available for download. The teacher will download it in advance to be able to show it to the class without the need for an internet connection. The school has a bandwidth of 50 megabits per second (Mbps). Calculate how long it will take the teacher to download the video. Use 1 GB = 1000 megabyte (MB). [2]

3.2 GB * (1,000 MB/1 GB) * (8 bits/1 Byte) * (1 sec/50 Mbits) = 512 seconds

Answers may include:
 convert 3.2 Gigabytes to Megabytes – 3.2 1000 3200MB  
 multiply by 8 to get it into Megabits – 25 600 Mbits
 divide by 50 to get the download time – 25600 512 50 seconds, or 8 minutes 32 seconds.

Award [1] for the correct calculation of file size 3200 MB.
Award [1] for the correct calculation into time.

(b) At the request of the principal, the network administrator has allowed teachers to download videos. Students are still not allowed to download videos at any time using the school internet. Analyse the impact this will have on the teachers and the students. [6]

Answers may include:

 teachers can download a video and save it to use it with class in the future
 teachers may have to stay after school hours if they want to download videos using the school internet as they may not have time to do it during the day
 teachers may have fewer problems with the video in class if it has been downloaded as the internet speed will not affect the playing of the video
 teachers may be better prepared for a lesson
 students may receive the a link to the videos to watch at home before the lesson
 internet speed will not affect the flow of the lesson when watching the video during a lesson
 students may ask for a copy of the video without having to use internet to download it or watch it
 students may resort to downloading study-related videos at home which could incur costs/consumption of bandwidth
 if the video is deleted/removed from the internet the teacher/student will still have a copy to use.

[1–2]: A limited response that demonstrates minimal knowledge and understanding of the impact of downloading videos using the school internet and uses little or no appropriate ITGS terminology.
[3–4]: A partial analysis, either lacking detail or balance, that demonstrates some knowledge and understanding of the impact of downloading of videos using the school internet. Some relevant examples related to the scenario are used within the response. There is some use of appropriate ITGS terminology in the response. Award a maximum of [4] if only the impact on teachers or students are addressed.
[5–6]: A balanced and detailed analysis of the issue which demonstrates thorough knowledge and understanding of the impact of downloading videos using the school internet. Relevant examples related to the scenario are used throughout the response. There is appropriate ITGS terminology throughout the response.

(c) One area that the working party will focus on is the responsible use of the available bandwidth. Some teachers have found that the internet is too slow to allow a class to investigate a topic when students in different classes are using social networking sites. To what extent can the implementation of the digital citizenship policies ensure the responsible use of technology in the school with respect to sharing the available bandwidth? [8]

Answers may include:
 policies without a previous education campaign /involvement of stakeholders may not work
 teachers/students may feel they can ignore the policies because they do not apply to their situation (e.g. downloading copyrighted videos to use in class because the school has insufficient bandwidth to stream them)
 digital citizenship policies are only as effective to the extent which all the stakeholders in the school community agree to follow them (e.g. students, teachers, parents, administrators etc.)
 the school may need to use technical solutions to support responsible use (e.g. blocking certain social networking sites, monitoring students network activities)

In part (c) of this question it is expected there will be a balance in the ITGS terminology between IT technical terminology and the terminology related to social and ethical impacts.