3.07 Parity Error Checking

3.7 Parity Error Checking Curriculum Page

Portfolio Reflection Questions:

1. Explain how the error card trick from the Error Detection lesson uses a parity scheme. Was it an even or odd parity scheme?

• The error card trick used in the Error Detection lesson uses an even parity scheme. I made sure that each row and column had an even number of cards facing up. In order to do this, I could add a face-up card at the end, or face-down.

2. What are some of the limitations of using parity bits for error detection?

• Some of the limitations of using parity bits for error detection include that an error can only be detected if an odd number of bits were flipped, but not even numbers. If an even number was flipped, the location of the error couldn't be determined.

3. Another type of error detection is a check sum. Research what a check sum is and then describe it in your own words. Can a check sum identify where an error occurs?

• A check sum is the resulting number after adding up blocks of digital data and dividing it by deductar. The check sum is used in order to make sure there are no errors after sending someone data. This can be checked by doing the math to make sure you have the same resulting check number. However, the problem with a check sum is that it has a large amount of room for error because it can't pinpoint where the error occurs. For example, if you sent a message: 35 24 15 11 with a check sum of 8, the other person could technically receive the same check sum but have the numbers, 36 23 15 11 (the math would cancel out the values).

4. (Optional) Explain in your own words the difference between error detection and error correction. Describe how the error correction process used in the video above allows the computer to fix errors.

• The difference between error deduction and error correction is that error deduction is only the discovery of whether there is error in data. However, error correction actually finds the location of the error and fixes it. The error correction process used in the video allows the computer to fix errors because it uses odd parity to fix the bits. If there was an error in the bits, shown by the three parity bits, it was corrected by switching a 0 to a 1, or vice versa.