11. 1 : DATA CAPTURE
SPECIFICATION STATEMENTS (AQA 5521)
Describe methods of data capture and identify appropriate contexts for their use
Understand the concept of data encoding
DATA and INFORMATION. What's the difference ?
Information has a CONTEXT which allows one to make sense of it.
RAW facts and figures are DATA. Once the context is added it becomes INFORMATION, and once you know what that MEANS it is KNOWLEDGE. An example of this is below.
ORGANISED facts and figures are INFORMATION. These have a CONTEXT which make them understandable.
For example:
15, 16, 17, 17
what does this mean ? - by itself it means nothing....
but what if I tell you that it's the price of 4 books, or the ages of 4 students. One of the values is less, so this is the cheapest book - using this information to make a decision is based on KNOWLEDGE.
Data is derived from different sources.
Data can be INPUTTED into a computer using different methods...
The INPUTS can be DIRECT or INDIRECT.
Examples of inputs include:
A CREDIT CARD being scanned so that information is taken from the magnetic strip.
An IMAGE from a web-cam.
INFORMATION downloaded from a SENSOR.
This is DIRECT ENTRY
One of the main examples of INDIRECT entry is someone typing data into a computer from a separate source e.g. someone entering data on student into a school administration system.
Information needs to have a number of characteristics. Ideally it should be:
UP TO DATE (this is sometimes not vital)
ACCURATE
RELIABLE (we need to assume it is correct...)
IN CONTEXT (understood by the user...)
CONSISTENT
Data needs to be VALID: this avoids the problem called GIGO: Garbage In, Garbage Out.
This is a real problem with many computer users...
One modern trend is the fact that INFORMATION HAS VALUE. The reason that many Supermarkets have LOYALTY CARDS is not due to altruism, but because they can track what people are buying.
Need to describe methods of DATA CAPTURE and identify appropriate contexts for their use. (Overlap with INPUT DEVICES)
Various methods of DATA CAPTURE include:
Optical Character Recognition (OCR) - many scanners now come with this feature built in (I have one) - it means that a worksheet can be scanned and turned into a WORD document
Optical Mark Recognition (OMR) - this is used in the registers that we have: SIMS, and also used by Exam boards for OBJECTIVE TESTS (or multi-choice as we used to call it....) - characters aren't recognised, but the presence of a pencil mark (or a BLACK PEN mark as they now seem to be) is noted... An amazing number of candidates (and invigilators) seem unable to carry out simple instructions on these...
Magnetic Ink Character Recognition (MICR) - printed on the bottom of cheques. They are able to be recognised as numbers, but the ink in them is magnetic which means that as the cheque is processed, this can be done at speed.
A question to consider: Why is it that there are more ways of Inputting data than there are of Outputting it ?
There is a link between this unit and that on the processing and storage of data in various formats.
It's important that for each of the various methods of DATA CAPTURE (and pieces of equipment), that the students are prepared for the following questions:
What they are
What equipment is necessary for this type of data capture - remember that this is not Computer Science, so there is no requirement to know exactly HOW it works
When it would be appropriate to use this method, and circumstances under which it would be used - named examples would be preferable here
Some advantages and disadvantages of the method - remember that nothing is perfect, even barcodes sometimes flash up the wrong code...
One type of data capture which is becoming more common is the touch screen. This is used in many RETAIL outlets now as a way of ensuring that the correct data gets entered by the operative. In PUBS for example, people working on the bar no longer have to add up or keep track of the cost of all the drinks, they just press buttons (or even pictures in some cases) of the items ordered and the total appears, along with how much change to count out...
Make sure you can talk about (include relevant diagrams to illustrate) the following ideas:
Keyboard Data Entry - different types of keyboard
Voice recognition software
Key to Disk systems
Bar Coding
OMR / OCR
Mice / Joysticks / Tracker Balls etc.
Hand held devices: bar code scanners / hand scanners
An interesting type of DATA CAPTURE is available to VIEW at VERILOCATION. This is a mobile phone and asset tracking service. Registered users of the service can track the location of consenting mobile phone users. This could be used by parents to keep tabs on where their children were (or at least where their child's mobile phone was....)