Lecture 2

Question 1

Data?

Answer 1

A collection of facts

Question 2

How is data obtained?

Answer 2

As the result of experiences, observations, or experiments

Question 3

What does data consist of?

Answer 3

Numbers
Words
Images

Question 4

Data source reliability?

Answer 4

Confidence and belief in this data source

Question 5

Data content accuracy?

Answer 5

The right data for the job

Question 6

Data accessibility?

Answer 6

Can we easily get to the data when we need to?

Question 7

Data security and privacy?

Answer 7

Allow people with authority only

Question 8

Data richness?

Answer 8

All the required data elements are required

Question 9

Data consistency?

Answer 9

Accurately collected and combined/merged

Question 10

Data currency?

Answer 10

Up to date

Question 11

Data granularity?

Answer 11

The variables be defined at the lowest level of detail for the intended use of the data

Question 12

Data validity?

Answer 12

Match/mismatch between the actual and expected data values of a given variable

Question 13

Data relevancy?

Answer 13

The variables in the data set are all relevant to the study being conducted

Question 14

Structured Data?

Answer 14

Targeted for computers to process

Numeric versus Categorical

Question 15

Unstructured/Textual Data?

Answer 15

Targeted for humans to process/digest

Question 16

Semi-Structured Data?

Answer 16

XML
HTML
Log files

Question 17

Categorical Structured Data?

Answer 17

Nominal

Ordinal

Question 18

Numerical Structured Data?

Answer 18

Interval

Ratio

Question 19

Unstructured Data contents?

Answer 19

Textual
Multimedia
XML/JSON

Question 20

What does data preprocessing include?

Answer 20

Data consolidation
Data cleaning
Data transformation
Data reduction

Question 21

Variables?

Answer 21

Dimensional Reduction

Variable Selection

Question 22

Cases/Samples?

Answer 22

Sampling

Balancing

Question 23

Data consolidation subtasks?

Answer 23

Access and collect the data
Select and filter the data
Integrate and unify the data

Question 24

Data consolidation popular methods?

Answer 24

SQL queries
Software agents
Web services
Domain expertise

Question 25

Data cleaning subtasks?

Answer 25

Handle missing values in the data Identify and reduce noise in the data Find and eliminate erroneous data

Question 26

Data cleaning, handling missing data popular methods?

Answer 26

Fill in the missing values with the most appropriate values

Question 27

Data cleaning, identifying and reducing noise in the data popular methods?

Answer 27

Identify the outliers in data with simple statistical techniques or with cluster analysis

Question 28

Data cleaning, finding and eliminating erroneous data popular methods?

Answer 28

Identify the erroneous values in data, such as odd values, inconsistent class labels, odd distributions

Question 29

Data transformation subtasks?

Answer 29

Normalize the data Discretize or aggregate the data Construct new attributes

Question 30

Data transformation, normalizing data popular methods?

Answer 30

Reduce the range of values in each numerically valued variable to a standard range by using a variety of normalization or scaling techniques

Question 31

Data transformation, discretize or aggregate data popular methods?

Answer 31

Convert the numeric variables into discrete representations using range-or-frequency-based binning techniques

Question 32

Data transformation, construct new attributes popular methods?

Answer 32

Derive new and more informative variables from the existing ones using a wide range of mathematical functions

Question 33

Data reduction subtasks?

Answer 33

Reduce number of attributes Reduce number of records Balance skewed data

Question 34

Data reduction, reduction number of attributes popular methods?

Answer 34

Principal component analysis Independent component analysis Chi-square testing Correlation analysis

Question 35

Data reduction, reduction of number of records popular methods?

Answer 35

Random sampling Stratified sampling Expert-knowledge-driven purposeful sampling

Question 36

Data reduction, balancing skewed data popular methods?

Answer 36

Oversample the less represented or undersample the more represented classes

Question 37

Statistics?

Answer 37

A collection of mathematical techniques to characterize and interpret data

Question 38

Descriptive statistics?

Answer 38

Describing the data as it is

Question 39

Inferential statistics?

Answer 39

Drawing inferences about the population based on sample data

Question 40

Mean Absolute Deviation?

Answer 40

Average absolute deviation from the mean

Question 41

Regression?

Answer 41

A part of inferential statistics The most widely known and used analytics technique in statistics Used to characterize relationship between explanatory and response variable

Question 42

What can regression be used for?

Answer 42

Hypothesis testing | Forecasting

Question 43

Correlation vs Regression?

Answer 43

Correlation is a single statistic or data point, where regression is the entire equation with all of the data points that are represented with a line

Question 44

How to develop linear regression models?

Answer 44

Scatter plots | Ordinary least squares method

Question 45

Regression Modelling Assumptions?

Answer 45

``` Linearity Independence Normality Constant Variance Multicollinearity ```

Question 46

What is a report?

Answer 46

Any communication artifact prepared to convey specific information

Question 47

Functions that report can fulfill?

Answer 47

``` To ensure proper departmental functioning To provide information To provide the results of an analysis To persuade others to act To create an organizational memory ```

Question 48

What is a business report?

Answer 48

A written document that contains information regarding business matters

Question 49

Purpose of business report?

Answer 49

To improve managerial decisions

Question 50

Source of business report?

Answer 50

Data from inside and outside the organization

Question 51

Format of business report?

Answer 51

Text + tables + graphs/charts

Question 52

Distribution of business report?

Answer 52

In-print Email Portal

Question 53

Steps of business report distribution?

Answer 53

Data acquisition -> Information generation -> Decision making -> Process management

Question 54

Types of Business Reports?

Answer 54

Metric Management Reports Dashboard-Type Reports Balanced Scorecard - Type Reports

Question 55

Data Visualization?

Answer 55

The use of visual representations to explore, make sense of, and communicate data

Question 56

Information visualization?

Answer 56

Aggregation, summarization, and contextualization of data

Question 57

Types of dimension reduction?

Answer 57

Variable Selection Principle Components Multi-dimensional scaling