Analog & Digital Information

Question 1

What is information vs data? Example?

Answer 1

Information is some knowledge that you want to record or transmit

Data is the representation of information

Information is a persons weight data is 65kg

Question 2

What is a signal?

Answer 2

A means to record or transmit data

Question 3

What are the two types of information? What are some examples?

Answer 3

Inherently continuous (infinitely many values in any range)
- mass, temperature, most physical properties, numbers between 1 and 10

Inherently discrete (finite number of values in any range)
- days in a week, number of steps walked, number of students on campus today

Question 4

What are the two main ways to represent info? What do they represent? Examples?

Answer 4

Analog: continuous representation, analogous to the actual info it represents

Ex. Mercury thermometers

Digital: discrete representation, uses finite number of digits or symbols to record data

Ex. Digital clock

Question 5

Are computers infinite or finite?

Answer 5

Finite

Can only operate in a fixed amount of data at a time, and the amount and type of data must be known ahead of time

Question 6

How can you represent information from an infinite range on a computer?

Answer 6

Need to represent enough of the range to meet our computational needs

Question 7

How do you convert analog data to digital data?

Answer 7

1. Sampling (discretization)
2. Quantization (truncation)

Question 8

What is sampling or discretization? Examples?

Answer 8

Converts continuous variation to discrete snapshots

Dividing a picture into pixels, frames per second in a video

Question 9

What is quantization or truncation? Example?

Answer 9

Converts infinite range of values to a finite one

1/3= 0.3 instead of repeating, pi is 3.14 instead of infinite

Question 10

Can information be lost when digitalizing? Is it ok?

Answer 10

Yes

Yes because we can decide what can be lost and there are mechanisms to determine the proper parameters to digitize info with as much precision necessary

Question 11

What is the basis of representing digital data? What is the unit symbol?

Answer 11

Binary digit or bit

b

Question 12

What are the two values of a bit?

Answer 12

0 or 1

Question 13

What are bits combined into a group of 8 called? What is the unit symbol?

Answer 13

Byte

B

Question 14

Why do use digital or binary data?

Answer 14

Computers cannot work well with analog data

Large range of values in analog representation

Using binary has cost and reliability benefits

Question 15

What are the benefits of digital data in signal transmission and storage?

Answer 15

Digital signals only have a high or low state

When transmitted signals degrade and it’s easier to determine what the original signal was in it only has a high or low state

Digital signals can be restored after degradation analog cannot