Data 200 Lect. 2, 3,4

• Data is represented in Binary

  • strings of 1 ands 0

  • small info = bits

• Binary Basics

  • 0 → 1

  • 1 → 1

  • 2 → 10

  • 3 → 11

  • 4 → 100

  • Base of 2

  • Always divide by 2

• Characters and More

  • ASCII table - converts hexadecimal and decimals into commands

• Colors

  • How to represent them?

  • RGB (###, ###, ###)

  • Hexadecimal (#RRGGBB)

  • each of the two-digit color codes are in the range 00…FF hexadecimal

• Data Groups

  • Structured Data

  • everything has a name and a type

  • relationship is defined between value and name

  • eg. spreadsheets

  • Unstructured

  • no implied relationship between values

  • Semi-structured Data

  • some portions are structures and some are not

• Files

  • CSV (Comma Separated Values)

  • text has quotes, numbers do not

  • each value is separated from other by commas

  • xml (eXentsible Markup Language)

  • XML extends HTML to provide structure for exchanging non-document information

  • eg. webpage

  • tsv (Tab Separated Value

  • same as CSV but separated by Tab

  • JSOM: Javascript Object notation

  • RSS (really simple syndication

  • dialect of XML

  • A lot of diff. ways data can be stored. in class mainly using CSV when incorporating data

• How to find dataset?

  • data.gov

  • dataset.google.com

Lect. 3

• Center of data

  • Mean

  • Median

  • Mode

• Spread

  • Standard Deviation

  • Range difference

  • St. dev range difference

  • range/SD

  • Z-score

  • (observed # - mean) /SD

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• Visualizing Data/Finding relationships

  • Histogram

  • if data is continuous, bars touch

  • Density plot

  • gives more info than a histogram

  • Bar plot

  • bars don’t touch

  • can arrange in any order

  • Scatter plot

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