Bar-code trail

Educational objective

To create and crack a code using a mobile phone.

Bar-code trail activity sheet

Download student activity sheet [pdf]

Key student learning

• There is hidden encoded information everywhere around us, such as on train tickets, credit cards and even household products.
• The way we use mobile phones nowadays has inspired engineers and IT scientists to improve the applications for mobile phones.
• Mobile phones can be important tools to support a wide variety of cognitive and social skills.
• Mobile phone games can support different tasks such as investigation, content generation, collaboration, problem-solving and navigation.
• Students can improve their research skills when looking for further information about the objects they choose for the trail.
• Students can also improve their writing skills in this activity as they can only use a limited number of characters for their secret message.

Materials needed

Students will need access to:

• Sticky tape or elastic bands.
• A bar-code creator. Examples can be found at Nokia, Kaywa or i-nigma.
• a 3G mobile phone (the links above will provide you with further information about which mobiles work with the bar codes).
• a printer.

Running the activity

• Using the bar-code creator on one of the websites listed (or any other version produced by a different mobile phone company), your students can produce bar codes for any items they choose. When the bar code is scanned by a mobile phone it will send a text message, which has been prepared by your students, giving information about that item.
• You can either allow students to select items of their choice or you can encourage them to pick objects in the classroom or school building that follow a theme of your choice such as ‘fluorescence’, ‘magnets’ or ‘polymers’.
• When it comes to producing the text message, you can decide the type of information your students need to write, e.g. an exciting fact about the object or an advertisement that would encourage the reader to buy it. Alternatively, you could also ask them to use the message to send a clue that leads the reader on a treasure hunt to the next object.
• Your students will only be able to use a maximum of 60 characters per message. This is a great way to get students to consider carefully how to put their message across, a skill that requires practice.
• When all the codes are ready and attached to objects around the classroom, students can go on a bar-code hunt to find and scan all the various codes to discover the secret messages that have been linked to them.

Discussion

• What advantages and disadvantages do mobile phone codes have compared with normal bar codes?
• Who might use the information? Have you seen them used in everyday life, e.g. in film posters?
• Who might want to use this type of coded information, e.g. marketing and product design companies?
• What other coding systems exist in our everyday lives?

Extensions

• Find more free online activities to offer your students.
• To run a Crime Lab theme in your science club, order our Crime Lab box. This box provides you with all the materials you need for three unique investigative activities. Your students can solve a crime by identifying fingerprints in a fuming chamber, decoding a magnetic swipe card and making castings of bite marks.

Links to everyday life

There is encoded information all around us and the way it has been encoded has changed through history.

Bar codes

As technology progresses there is a need to pack more and more information onto cards. And because this requires more space for the code than current cards can provide, new types of bar codes have to be invented. The technology began with simple black-and-white line codes, and was followed by layered or ‘matrix’ codes in the 1990s. Now mobile phones are able to read a variety of specially designed mobile bar codes. This has only been made possible by recent advances in bar-code reader technology that have allowed cameras in mobile phones to act as code readers.

Other coding systems

Image of 'Cooke and Wheatstone double-needle telegraph'

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This particular Cooke and Wheatstone double-needle telegraph was built in 1844 and installed at a railway station in Slough, Berkshire. It was not used for railway signalling purposes, like other telegraphs, but for sending and receiving messages at the various stations. This instrument gained widespread publicity in 1845 when it received a message that led to the immediate arrest of a notorious murderer. The coding system of this double-needle telegraph is quite complicated, but it is actually very similar to how text messages on mobile phones are set up. You will find the Cooke and Wheatstone double-needle telegraph in the Telecommunications gallery at the Science Museum.