Course 4: Module 2

Question 1

Dirty data

Answer 1

Data that is incomplete, incorrect, or irrelevant to the problem you’re trying to solve

Question 2

Clean data

Answer 2

Data that is complete, correct, and relevant to the problem you’re trying to solve

Question 3

Null

Answer 3

An indication that a value does not exist in a dataset

Question 4

Duplicate data

Answer 4

Any data record that shows up more than once

Question 5

Outdated data

Answer 5

Any data that is old which should be replaced with newer and more accurate information

Question 6

Incomplete data

Answer 6

Any data that is missing important fields

Question 7

Incorrect/Inaccurate data

Answer 7

Any data that is complete but inaccurate

Question 8

Inconsistent data

Answer 8

Any data that uses different formats to represent the same thing

Question 9

Field

Answer 9

A single piece of information from a row or column of a spreadsheet

Question 10

Data validation

Answer 10

A tool for checking the accuracy and quality of data before adding or importing it

Question 11

Data merging

Answer 11

The process of combining two or more datasets into a single dataset

Question 12

Compatibility

Answer 12

How well two or more datasets are able to work together

Question 13

Common mistakes to avoid

Answer 13

• Not checking for spelling errors
• Forgetting to document errors
• Not checking for misfielded values
• Overlooking missing values
• Only looking at a subset of the data
• Not fixing the source of the error
• Not analyzing the system prior to data cleaning
• Not backing up your data prior to data cleaning
• Not accounting for data cleaning in your deadlines/process

Question 14

Conditional formatting

Answer 14

A spreadsheet tool that changes how cells appear when values meet specific conditions

Question 15

Remove duplicates

Answer 15

A tool that automatically searches for and eliminates duplicate entries from a spreadsheet

Question 16

Text string

Answer 16

A group of characters within a cell, most often composed of letters

Question 17

Split

Answer 17

A tool that divides text around a specified character and puts each fragment into a new, separate cell

Question 18

Concatenate

Answer 18

A function that joins multiple text strings into a single string

Question 19

COUNT IF

Answer 19

Returns the number of cells that match a specified value

Question 20

Syntax

Answer 20

A predetermined structure that includes all required information and its proper placement

Question 21

Len

Answer 21

A function that tells you the length of a text string by counting the number of characters it contains

Question 22

LEFT

Answer 22

A function that gives you a set number of characters from the left side of a text string

Question 23

RIGHT

Answer 23

A function that gives you a set number of characters from the right side of a text string

Question 25

MID

Answer 25

A function that gives you a segment from the middle of a text string

Question 26

Trim

Answer 26

A function that removes leading, trailing, and repeated spaces in data

Question 27

Pivot table

Answer 27

A data summarization tool that is used in data processing

Question 28

VLOOKUP

Answer 28

A function that searches for a certain value in a column to return a corresponding piece of information

Question 29

Data mapping

Answer 29

The process of matching fields from one data source to another

Question 30

Compatibility

Answer 30

How well two or more datasets are able to work together

Question 31

Schema

Answer 31

A way of describing how something is organized