Chapter 3: Data

Bits

are grouped to represent abstractions. 

Abstractions

find common features to generalize the program.

analog signal

has values that change smoothly over time, rather than in discrete intervals.

digital signal

is an analog signal that has been broken up into steps.

variable

is an abstraction inside a program that can hold a value. 

value

can be a list or other collection that, in turn, contains multiple values. 

overflow error

occurs when the result of a computation is too large for the available storage space.

roundoff error

occurs when decimals (real numbers) are rounded. 

Data compression

is reducing the size (number of bits) of transmitted or stored data.

Digital data compression

often involves trade-offs in quality versus storage requirements.

Lossy compression

can significantly reduce the file size while decreasing resolution. 

Lossless data compression

no data are lost. 

Information

is the collection of facts and patterns extracted from data.

Cleaning data

is a process that makes the data uniform without changing their meaning.

Predicting algorithms

use information collected from big data to influence our daily lives.

Visualization

tools can communicate information about data. 

Privacy concerns

arise through the mass collection of data

Geolocation

when used within a program, helps you find the approximate geographic location of an IP address along with some other useful information, including ISP, time zone, area code, state, and so on.

Metadata

are data that describe your data