big idea 2

• Bits are grouped to represent abstractions. These abstractionsinclude but are not limited to numbers, characters, and colors. Ab-stractions find common features to generalize the program. Thiscan also help shrink the code if you are planning to use a method/procedure more than once in a program.
• High-level languages contain the most abstractions and allowfor easier coding and easier debugging.
• Analog signals are continuoussignals, while digital signals are discrete time signals.
• A digital signal is an analog signal that has been broken up intosteps. Analog data can closely approximate digital data using asampling technique, which means measuring values of the analogsignal at regular intervals called samples. The samples are measured to figure out the exact bits required to store each sample. Thesmaller the sample rate, the more accurately the digital signal represents the analog signal.
• some computer languages do have limits on the size of data types.
• A variable is an abstraction inside a program that can hold a value.Each variable has associated <lata storage that represents one valueat a time. However, value can be a list or other collection that, inturn, contains multiple values. Some <lata types include integers,real numbers, Boolean, string, and list.
• Number bases, including binary, decimal, and hexadecimal, areused to represent and investigate digital data.
• when converting binary numbers to decimal numbers we write the multiples of 2 but start with one starting from the right,we write the binary number starting from the left then multiply the numbers that align with eachother and sum them up
• when converting decimal to binary start writing from the first multiplaince of two that is smaller than our decimal number. write one under that than take that multiplaince of two out of the decimal number and check if the next biggest multiplaince of two is smaller if it is write one if it is not write zero and keep going
• A roundoff error occurs when decimals (real numbers) arerounded. One computer might calculate 1/3 as O. 333333. Anothercomputer might calculate 1/3 as 0.3 333333333. in this case, 1/3on one computer is not equal to 1/3 on a second computer.
• Data compression is reducing the size (number of bits) of transmitted or stored data. Fewer bits does not necessarily mean lessinformation
• Lossy compression can significantly reduce the file size whiledecreasing resolution. Traditionally, lossy compression is used toreduce file size for storage and transmission (email). The tradeoff of using lossy data is that you will not recover the original file.Some data will be lost.
• in lossless <lata compression, no data are lost. After compression, the original file can be reproduced without any lost data. Thetrade-off of lossless data compression is larger files that can bedifficult to store, transfer, and handle.Lossless (left) and lossy (right) <lata compression
• People can use computer programs to process information aswell as to gain insight and knowledge. Information is the collection of facts and patterns extracted from data.
• Data sets pose challenges regardless of size, such as:■ The need to clean data■ lncomplete data■ lnvalid data■ The need to combine data sources
• Cleaning data is a process that makes the data uniform withoutchanging their meaning.
• Problems of bias are often created by the types and sources of<lata being collected. Bias is not eliminated by simply collectingmore <lata. A large amount of <lata is generated by humans. Algorithms that use this <lata will reflect this bias.
• interpreted : yorumlanmış
• obsolete : modası geçmiş
• Metadata are data that describe your data-for example, a pictureof you standing in front of a waterfall is data. The location andtime the picture was taken are metadata. Metadata are used forfinding, organizing, and managing information.Metadata can increase the effective use of data or data sets byproviding additional information about various aspects of that data.
• Changes and deletions made to metadata do not change theprimary data.Putting an image of Niagara Falls behind Novack the3rd in the photo on page 14 7 will not change the location metadataof where the picture was taken