Imagine a future where humans are unable to access the data, literature, art, photographs, discoveries, and vital records of previous generations. That bleak future may be on the horizon! Learn how our fragile, rapidly-obsolete systems of storing data could lead to a digital dark age. This video comes with discussion questions.
Computers talk to each other over the internet via messages. However, the internet is not reliable and sometimes these messages get lost. There are certain bits of information we can add to messages to make sure they are sent. This information makes up a protocol.
In this activity, students consider how different methods of communication operate successfully. By looking at rules and procedures in place, students are introduced to communication protocols. By working through a role-play scenario, pupils test their own protocol operating in an unreliable environment similar to that found in packet switching on the Internet, specifically, TCP/ IP.
On the internet, data is broken into packets for transportation. However, the channels in which these packets travel is not always reliable. Individual packets sometimes are damaged, lost or lose their ordering.
In the game Tablets of Stone, tablets are packets and their content is data. Packets contain both data and header information. The size of the header information affects how much data can be transferred – so a balance has to be reached, as packets are of finite size.
Students will find that they will need to swap some of their data boxed for information such as packet number and total packets, or whether or not the packet is an acknowledgment packet. Due to this information taking up data boxes, overall more packets will be needed.
Many computer users are familiar with compressed formats such as zip, gzip, or gif images. These are based on a method called Ziv-Lempel coding, which turns out to be an interesting exercise in finding patterns in text.
Children’s rhymes and stories are good examples of text compression because they often involve repeated words and sequences.
The world is a noisy place, and errors can occur whenever information is stored or transmitted. Error detection techniques add extra parity bits to data to determine when errors have occurred.
This activity is a magic trick which most audiences find intriguing. In the trick the demonstrator is “magically” able to figure which one out of dozens of cards has been turned over, using the same methods that computers use to figure out if an error has occurred in data storage.
This activity involves listening to songs and finding hidden messages based on the same principle as a modem.
The binary number activity briefly mentions how text could be coded using sound — high and low beeps represent binary digits, which in turn can be decoded to numbers that represent the letters of the alphabet.
All data on computers is stored and transmitted using the binary number system. When the binary digits need to be sent over phone lines which used to be standard in home internet connections, the digits are converted to sound and decoded at the other end, using a modem. This activity uses an audio coding similar to that used by a modem, but the sounds are recorded as songs, which students can decode.
This activity provides several ways to introduce students to databases, with follow-up lesson extensions for increasing database understanding.
This report gives details of a series of computing lessons designed to relate fundamental concepts of database use and design to children in Primary and Secondary Education (ages of 6 to 16). The skills and concepts developed in these lessons begin at a very simple level but progress to cover abstract concepts such as Relational Databases. The series has been aligned to match the scope, range and targets recommended in the Computing At Schools document A Curriculum for Computing.
Contents:
This activity concludes with a “plugged-in” activity using a database system. The Digital Schoolhouse Database Detectives lesson is aimed at Key Stage 2 pupils and based on the book Certain Death by Tanya Landman. Before completing the series of database unplugged activities, the class teacher is encouraged to read the book (except the last chapter) and complete a series of encryption activities loosely based on the book, the answers providing pupils with the clues to question the database and identify the murderer.
Pupils use cloud computing technology e.g. Google Documents: Spreadsheets, to collaboratively input data about the suspects from profile cards based on the book. Pupils then perform verification on their neighbor’s data entry before downloading the spreadsheet and importing it into Microsoft Access. After importing the data, pupils first use the filter tool to solve the murder using the answers from the numeracy challenges, then create a report for the Court based on a query identifying the murderer.
In this lesson, students look at how data is collected and used by organizations to solve problems in the real world. The lesson begins with a quick review of the data problem-solving process they explored in the last lesson. Then students are presented with three scenarios that could be solved using data, brainstorm the types of data they would want to solve them, and how they could collect the data. Each problem is designed to reflect a real-world service that exists. After brainstorming, students watch a video about a real-world service and record notes about what data is collected by the real-world service and how it is used. At the end of the lesson, students record whether data was provided actively by a user, was recorded passively, or is collected by sensors.
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