Input Devices - advantages and disadvantages of each Flashcards
Keyboards
Advantages
Enables fast entry of new text into a document
Well tried technology and well known method of entry
Most people find them easy to use
Easy to do verification check as data is entered, as it appears on the screen simultaneously
Disadvantages
Users with limited arm/wrist use can find keyboards hard to use
Entering data is slow when compared to direct data entry (e.g. Optical mark recognition)
They use up desk space as they are quite large
Concept Keyboard
Advantages
Enables fast data entry (there is no need to type in whole commands)
Waterproof, useful in a restaurant environment
They are tamperproof, preventing people from keying in information (which could corrupt the
system)
Mouse
Advantages
Faster to select an option by a mouse than a keyboard
Enables rapid navigation through applications and the internet
Mice are small and don’t take much area
Disadvantages
People with restricted hand/wrist movement can find it hard to operate a mouse
Easily damaged and can easily be clogged up with dirt
They are hard to use if there is no flat surface available
Touchpads
Advantages
Faster to select an option by a touchpad than a keyboard
Enables rapid navigation through applications and the internet
Since the touchpad is integrated into the laptop computer, there is no separate mouse, aiding portability
They can be used when no flat surfaces are available
Disadvantage
People with limited hand/wrist movement can find touchpads hard to use
It can be more difficult to control the pointer when compared to a mouse
They are more difficult when doing operations such as ‘drag and drop’
Joysticks
Advantages
Easier to navigate round a screen compared to a keyboard
Control is in three dimension
Disadvantages
More difficult to control the on-screen pointer with a joystick than with other devices such as mice
Touchscreens
Used for service tills e.g. petrol stations
Used where selections are made on a screen e.g. ATMs, public
information systems, airports and railway stations
Advantages
Enable faster entry of options than a keyboard or a mouse
Very easy to choose options
User friendly method for inputting data
They are tamperproof, preventing people from keying in information (which could corrupt the system)
Disadvantages
There is a limited number of options available
Using touchscreens often can lead to health problems e.g. (straining of arm muscles and RSI)
The screen can get very dirty with constant touching
Magnetic Stripe readers
Advantages
Data entry is fast compared with keying in using a keyboard or keypad
System is error free, no typing involved
Information is secure since there is no typing and the information can’t be read directly by a person
Can prevent access to restricted/secure areas
Magnetic stripes are unaffected by oil water and moisture
No moving parts therefore physically robust
Disadvantages
If the magnetic stripe is damaged the data is lost
Card needs to be in close contact with the reader
Since the information is not human readable, they need to find a way to show the information to the customer (e.g. hotel room number not printed on cards)
Scanners
Advantages
Images can be stored for editing at a later date
Scanners are much faster and more accurate than typing in documents again
It is possible to recover damaged documents and photographs by scanning them and then using appropriate software to produce an acceptable copy
Disadvantages
The quality can be limited depending on how good the scanner resolution is
Barcode readers
Advantages
Faster than keying in information, and fewer mistakes are made
Used as a way of recording data, can improve safety
Barcodes enable automatic stock control
Barcode scanning is a tried and trusted technology
When an item price is changed, only the central database needs to be updated, there is no need to change the prices individually on each item
Disadvantages
Barcode scanning is an expensive system to administer since every item in the shops needs a barcode and every barcode needs to be entered on the system.
Also there is a need to invest in the
computer technology together with staff training, which can all be expensive
The system is not fool proof- barcode can be swapped around on items
OMR Devices
Advantages
A very fast way of inputting results of a survey
Since there is no typing, it is more accurate than keying in data
OMR is more accurate than OCR
Disadvantages
Forms need to be carefully designed to make sure that the marks/shadings are correctly positioned to gather accurate information
There can be problems if forms aren’t filled correctly, sometimes they have to be checked manually
before being read by an OMR, this is both time consuming and expensive
MICR Device
Used to process cheques in banking operations – cheque is
read using a batch processing method
Advantages
MICR offers great security than OCR since the oriented characters cannot be altered
There is no manual input, thus errors are reduced
If somebody writes over the magnetic ink characters it can still be read
Disadvantages
Only certain characters can be read and the number of different characters is very limited
It is a more expensive method than other methods used for direct data entry
Digital Cameras
Advantages
Easier to produce better quality photographs than with a tradition camera
Easier and faster to upload photographs to a computer
There is no need to develop film and print out photographs (saves paper and no longer needs the chemicals to produce photographs from films)
Easy to delete an image from the memory if it’s not satisfactory
The memory card can store several hundred photographs
Disadvantages
The camera user needs to be computer literate to use the camera properly
There is some artistry lost since clever software corrects errors in the photographs
The resolution is not yet as good as traditional cameras
Images often need to be compressed to reduce the amount of memory used
It is possible to fill up computer memory very quickly with several photos of the same subject(in order to find the perfect snap shot)
Webcams
Advantages
Can be left on constantly and activated when required
Allow people to keep in contact with each other without the need to travel, particularly useful for disabled or elderly people
Disadvantages
Webcams have limited features and the picture is often of poor quality
They need to be connected to a computer
Microphone
Advantages
Faster to read in text than to type it using a keyboard
Possible to manipulate sound in real time using special software
If used in a voice activation system, this has the advantage of improving safety
Disadvantage
Sound files can use up a lot of computer memory
Voice recognition software isn’t as accurate as typing in manually
Sensors - examples: Temperature Pressure Light Sound Humidity/moisture pH
Advantages
Readings by sensors are more accurate than taken by humans
Readings are continuous, there is no break in monitoring
Because it is a continuous process any necessary action or warning will be initiated immediately
The system can be automatic, removing the need for human intervention, this is particularly important if the process is hazardous
Disadvantages
Faulty sensors can give spurious results
