Computer Basics - Input

1. Computer Basics - Input Data Automation

2. Data Automation • Goals: • Avoid mistakes in data entry by making the initial entering of the data as automatic as possible. • Avoid having to re-enter data to perform a different task with it.

3. General Devices • Scanner - creates a digital image of what it scanned.  Scanned text cannot be edited at this point. • Flat bed scanners open wide enough to allow you to lay a document or book flat on the glass surface. • A document scanner can only scan individual sheets of paper, not books or objects.

4. General Devices • Bar-Code Scanner - Hand-held or fixed devices that can read the bar codes on packages. • Credit Card Reader - Swipe the credit card through the device, which reads the magnetic numbers in the magnetic strip on the card.

5. Special Types of Characters • Bar Codes - Retail shops now use printed bar codes on products to track inventory and calculate the sale at the checkout counter. • The US Post Office uses bar codes to sort mail, but the bars are different from those used for pricing products.

6. Special Types of Characters • Optical Marks - A special machine "reads" the marks. Example - test scoring. • Magnetic Ink - Bank account # is printed in special ink with magnetic qualities which can be read by the right machine.

7. Special Types of Characters • Magnetic Strip - The back of a credit card has a magnetic strip that contains magnetically encoded numbers. A credit card reader can read the numbers and transmit them to a computer to verify that the card is good. • Optical Characters - There are coding systems that use letters or special characters that are especially shaped to be easy for machines to read.

8. Special Types of Characters • RFID - Radio Frequency Identification uses special tags that contain chips which are programmed with information. • A RFID reader device sends a signal to the chip which makes the tag send a short-range radio signal with the information.

9. RFID • Examples: • shipping containers - what's in the container, where it came from, where it is going • surgery equipment - to get a count of items to make sure none are still in the patient • patient ID bracelet - patient name, medical info • pet ID tag - pet's name, medical info, owner's name and contact info • library book - book ID for automatically checking books out and back in • product on store shelf - auto-scan at checkout, out-door scanning for theft, auto-update of inventory

10. OCR Software  • Optical Character Recognition: This software takes a scanned image and converts the characters in the image into computer characters. • The document can now be edited with a word processor.

11. Computer Basics - Input Data Accuracy

12. Data Accuracy GIGO =  Garbage In, Garbage Out

13. Checking for Accuracy • A program should attempt to do the following: • test data type and format • ex. 2/a/96 is not a date • ex. If a phone number should have exactly 10 digits with the area code, then 555-123 is not acceptable. • test data reasonableness • ex. 231 should not be a person's age • ex. A sale of $50,000 worth of chewing gum at the corner market is probably missing a decimal point

14. Checking for Accuracy • A program should attempt to do the following: • test data consistency • ex. A man's death date should be later than his birth date! • ex. The sum of the monthly paychecks should be the same as the total paid for the year. • test for transcription and transposition errors • ex. Typing 7754 instead of 7154 is a transcription error, typing the wrong character. • ex. Typing 7754 instead of 7745 is a transposition error, interchanging two correct characters.