week 2 Nature and forms of data

Question 1

why is statistics relevant in business

Answer 1

Statistics plays an important role in virtually all aspects of business (e.g. strategy, marketing, operations, supply chain).

Question 2

what are some common applications
of statistics in business

Answer 2

Common applications of statistics include predictive modelling, pattern recognition, anomaly detection, classification, and sentiment analysis.

Question 3

Data analysis cycle. statistical enquiry cycle.

Answer 3

problem: define the problem. question and hypothesis

plan: study design and variables

data: collect and treat dataset

analysis: exploratory data analysis (EDA)
Modelling effort
Relating findings with context

Conclusion:
answer the question
present results and insights
new questions may emerge

Question 4

Data science process

Answer 4

The data analysis process includes a set of activities that business analysists/ data scientists perform to gather, prepare, analyse data, and present the results/ findings to business users

Question 5

What are the two main categories in which data collection is typically distinguished, and why is data collected.

Answer 5

data is collected for specific purposes

In terms of data collection, it may be distinguished between primary and secondary.

Question 6

what is primary data

Answer 6

Primary data refers to data collected directly from the data source without going through any existing sources (e.g. survey conducted by a researcher, answers of an online questionnaire).

Question 7

what is secondary data

Answer 7

Secondary data consists of data previously collected and compiled by someone else (e.g. stock market index).

Question 8

Data vs information

Answer 8

data:
raw facts or figures
Meaningless and useless until it is organised and processed
understanding is commonly difficult
input is treated as data

information:
data with context
processed and meaningful form of data
understanding is comparably easier
output is treated as information

Question 9

qualitative data

Answer 9

Qualitative data are names or labels used to identify an attribute of each element.It may be numeric or nonnumeric (use the nominal or ordinal scale).

Question 10

quantitative data

Answer 10

Quantitative data represent measurements or counts.It is always numeric (use the interval or ratio scale).

Question 11

what does the level of measurement determine

Answer 11

The level of measurement determines the amount of information contained in the data.

Question 12

what does the level of measurement also indicate

Answer 12

The level of measurement also indicates the data summarisation and statistical analyses that are most appropriate.

Question 13

what are the four levels of measurement

Answer 13

There are four levels of measurement: nominal, ordinal, interval, and ratio.

Question 14

what does nominal data consist of

Answer 14

Nominal data consists of labels or names used for identification, may be non-numeric or numeric.

Question 15

information about nominal data

Answer 15

The categories are in no logical order and have no particular relationship. The categories are said to be mutually exclusive since an individual, object, or measurement can be included in only one category.

Question 16

what does ordinal data consist of

Answer 16

Ordinal data exhibits properties of nominal data and may be rank-ordered.

Question 17

what does interval data consist of

Answer 17

Interval data have the properties of ordinal data but also show uniform distances between successive values.

Question 18

what does ratio data consist of

Answer 18

Ratio data have all the properties of interval data and the ratio of two values is meaningful.Scale must have a natural zero point (i.e. there is a nonarbitrary zero point).

Question 19

nominal, ordinal, interval and ratio data

Answer 19

nominal: variable is only named
ordinal: variable is named and ordered
interval: variable is named, ordered, and proportionate interval
ratio: variable is named, ordered, proportionate interval, and considers absolute zero

Question 20

Big Data

Answer 20

Big data refers to the large and diverse sets of information that grow at ever-increasing rates.

Three V’s of Big Data: The volume of information, velocity (or speed) at which data are created and collected, and the variety of data available.

Big data often comes from data mining and arrives in multiple formats.