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

Scales: 

• Scaling is the process of measuring.

Measurement Scales:

Measurement scales are used to categorize and/or quantify variables.

A measurement scale is used to qualify or quantify data variables in statistics. It determines the kind of techniques to be used for statistical analysis.

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.
• In ordinal scales, numbers represent rank order and indicate the order of quality or quantity, but they do not provide an amount of quantity or degree of quality.

Example:

• The number 1 means that the person (or object or event) is better than the person labeled 2; person 2 is better than person 3, and so forth. 
• How are you feeling today?  a. Very Unhappy, b. Unhappy, c. OK, d. Happy, e. Very Happy
• How satisfied are you with our service? a. Very Unsatisfied, b. Unsatisfied, c. Neutral, d. Satisfied, e. Very satisfied
• 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.
• Interval scales are numeric scales in which we know both the order and the exact differences between the values.

Examples:

• 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.

• Time of each day in the meaning of a 12-hour clock.
  Grade levels in a school (1st grader, 2nd grader, and etc.)
• Voltage e.g. 110 and 120 volts (AC); 220 and 240 volts (AC) and etc.
• Dates (1015, 1442, 1726, etc.)
• Measuring an income as a range, like $0-$999; $1000-$1999; $2000-$2900, and etc. This is a classic example of turning a non-interval, ordered variable scale into an interval scale to support statistical analysis.
• Age is also a variable that is measurable on an interval scale, like 1, 2, 3, 4, 5 years and etc.
• IQ test (intelligence scale).
• Temperature, in degrees Fahrenheit or Celsius (but not Kelvin).

Ratio Scale

• It possesses all the characteristics of the interval measurement, and there exists a true zero.
• Ratio scale is a type of variable measurement scale which is quantitative in nature. Ratio scale allows any researcher to compare the intervals or differences.

Examples:

• Weight of a packet of candy.
• Height of a boy,
• Age.
• Sales Figures.
• Ruler measurements.
• Income earned in a week.
• Years of education.
• Number of children

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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

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Introduction to Statistics

                                                               

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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 numerical information (numbers). It can farther be divided as:

• 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 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.

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What is Statistics?

What is Statistics?

History of word to Statistics?

The word Statistics has been derived from a Latin word “status” or the Italian word “statista”, and meaning of these words is “political state” or “government”.

What is Statistics?

Statistics is the science of conducting studies to identify, collect, organize, summarize, analyze and draw conclusions from Data.

Art of learning from data.

Examples:

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