An Introduction to the Science of Statistics
Thursday, February 6, 2020
Tuesday, February 4, 2020
Measurement Scales or Levels
Measurement Scales or Levels
Measurement Scales?
Measurement
Assignment of numbers to Characteristics (variables) of objects, persons or events
Measurement is the foundation of any scientific investigation
Measurement is the foundation of any scientific investigation
Scales:
Scaling is the process of measuring.
Measurement Scales:
Measurement scales are used to categorize and/or quantify variables.
Nominal Scale:
- It classifies data into mutually exclusive (overlapping), exhausting categories in which no order or ranking can be imposed on the data.
- Assign responses to different categories, having no numerical difference.
- It also called the categorical variable scale, is defined as a scale used for labelling variables into distinct classifications and doesn’t involve a quantitative value or order.
- It just assign the label to the data by category-wise i.e. Male, Female
Examples:
- Gender: 1=Male, 2=Female (It doesn't matter that what is the number of male or female).
- What about symptoms of depression from a psychiatric assessment? None=0, Mild=1, Moderate=2, Serve=3
- Where do you live? 1- Suburbs 2- City 3- Town
Nominal scale is often used in research surveys and questionnaires where only variable labels hold significance.
For instance:
- A customer survey asking “Which brand of smartphones do you prefer?” Options: “Apple”- 1, “Samsung”-2, “Oppo”-3, "Infinix"-4.
- Why do you like the above chosen brand for best? Options: “OS”- 1, “Battery”-2, “Design”-3, "Weight"-4.
Ordinal Scale
- It classifies the data into categories that can be ranked; however, precise differences between the rank do not exist.
- Set of categories that are ordered from least to most.
- Position in a Race, 1st, 2nd, 3rd, 4th and so on...
- Govt jobs Grade BPS-1, BPS-2, BPS-14 etc
- Military Rank
- Grades
- Satisfaction
- Happiness
Interval Scale
- It ranks data and precise differences between units of measure do exist; however, there is no meaningful zero.
- It is defined as a numerical scale where the order of the variables is known as well as the difference between these variables.
- Temperature is on the Interval Scale: a difference of 10 degrees between 90 and 100 means the same as 10 degrees between 150 and 160.
Ratio Scale
- It possesses all the characteristics of the interval measurement, and there exists a true zero. .
Examples:
- Weight of a packet of candy.
- Height of a boy,
Data Collection and its Sources
Data Collection and its Sources
Data Collection:
Data collection is the process of collecting or gathering data on any specific variable topic.There are two ways to collect the data.
PURPOSE OF DATA COLLECTION
The purpose of data collection is- to obtain information
- to keep on record to make decisions about important issues,
- to pass information on to others
Sources of Data Collection
There are two sources of data collection:
Primary Data:
Primary data is information collected through original or first-hand research.
For example: surveys and focus group discussions.
Secondary Data:
Secondary data is information which has been collected in the past by someone else.
For example: researching the internet, newspaper articles and company reports
Measurement Scales
Monday, February 3, 2020
What is data?
What is data?
Data:
Data is a collection of facts, such as numbers, words, measurements, observations or even just descriptions of things.Types of Data:
Qualitative data:
Qualitative data is descriptive information (it describes about something).Quantitative data:
Quantitative data is the s numerical information (numbers).
- Discrete data can only take certain values (like whole numbers)
- Continuous data can take any value (within a range)
Example: What do you know about the dog?
Qualitative:
- He is brown and black
- He has long hair
- He has lots of energy
Quantitative:
Discrete:- He has 4 legs
- He has 2 brothers
Continuous:
- He weighs 25.5 kg
- He is 565 mm tall
Data or Datum?
Datum is is a singular i.e.we say "that datum is very high".
Data is the plural i.e. we say "the data are available",
but data is also a collection of facts, so "the data is available" is fine too.
but data is also a collection of facts, so "the data is available" is fine too.
Measurement Scales
Basic Concepts
