1. By marius OMR Web cam Light pen Light sensor

2. OMR(optical mark recognition) Uses This device is used to mark big multiple choice papers Advantages An OMR scanner can maintain a throughput of 1,500 to 10,000 forms per hour. This can be controlled by a single PC workstation It consistently provides unmatched accuracy when reading data data can be recorded on an OMR form even when a PC or network goes down. Disadvantage Uses electricity

3. Web cam Uses It can be used for live video streaming with people in other country's or for business meetings Advantages can be an extremely valuable tool when connected with the Internet Web cameras allow people to have the sensation that they are in close contact with another person Disadvantages Relies on the internet People might rely on webcams to much and there social skills could slip away

4. Light pen Uses They are used to draw directly onto the screen advantages Can draw directly on the screen Light pens are easy to use They have extremely good positional accuracy on a computer screen When used for bar code reading, they are lightweight, able to come in direct contact with the bar codes and have no moving parts. Disadvantages Light pens are easily damaged They can only be used on some computer screens they do not work with LCD screens They usually lack high resolution capability

5. Light sensors Uses They are used to sense the amount of light going through the sensor and produces an output signal