By Noel P. Munda, LPT, MAEd
January 19, 2022
What are the levels of measurement?
To perform statistical analysis of data, it is important to first understand variables and what should be measured using these variables.
There are different levels of measurement in statistics and data measured using them can be broadly classified into qualitative and quantitative data.
First, let’s understand what a variable is.
A quantity whose value changes across the population and can be measured is called a variable.
For instance, consider a sample of employed individuals.
The variables for this set of the population can be industry, location, gender, age, skills, job-type, etc. The value of the variables will differ with each employee.
The level of measurement of a variable decides the statistical test type to be used.
The mathematical nature of a variable or in other words, how a variable is measured is considered as the level of measurement.
Nominal, Ordinal, Interval, and Ratio are defined as the four fundamental levels of measurement scales that are used to capture data in the form of surveys and questionnaires, each being a multiple-choice question.
NOMINAL
They are named variables.
It is also called the categorical variable scale.
It is defined as a scale used for labeling variables into distinct classifications.
It does not involve a quantitative value or order.
It is a naming scale, where variables are simply “named” or labeled, with no specific order.
EXAMPLES:
1. Phone preference: “Which brand of smartphones do you prefer?”
Options: 1-Apple, 2-Samsung, 3-Vivo, 4-Oppo
2. Place of residence: “Where do you live?”
Options: 1- Suburbs, 2- City, 3- Town
3. Gender
Options: 1-Man, 2-Woman, 3-Transgender, 4-Intersex, 5-Gender Queer
4. Sex
Options: 1-Male, 2-Female
5. Political preferences:
Options: 1- PDP-LABAN, 2- Liberal Party, 3- United Nationalist Alliance
6. Dichotomous (2 options, i.e., Yes/No, T/F, etc.)
ORDINAL
They are named plus ordered (ranked) variables
It has all its variables in a specific order, beyond just naming them.
It is defined as a scale used for labeling variables into distinct classifications that are ordered.
The origin of this scale is absent due to which there is no fixed start or “true zero”.
EXAMPLES:
1. Likert scale
Options: 4-Strongly Agree, 3-Agree, 2-Disagree, 1-Strongly Disagree
2. Educational Attainment
Options: 1- Elementary, 2- High School, 3- College, 4-MBA/MAEd, 5-PhD/EdD
3. Grade or Year Level
Options: 1-First, 2-Second, 3-Third, 4-Fourth
4. Options: 1-Better, 2-Same, 3-Worse, 4-Worst
INTERVAL
They are named plus ordered plus proportionate interval between variables.
Continuous, meaning that each value of the variable is one increment larger than the previous and one smaller than the next value
It offers labels, order, as well as, a specific interval between each of its variable options.
It has no true zero / cannot accommodate the value of zero. Eg. 0 degree C (It does not mean No temperature)
EXAMPLES:
1. Temperature (in Celsius or Fahrenheit, i.e., 37° C.)
2. Years (Eg. 2019, 2020, 2021, etc.)
3. Age (if measured in years, i.e., 25 years old, etc.)
4. Attitude scales
5. Semantic Differential Scale
Eg. Slider Rating Scale
Very Pleasant, Somewhat Pleasant, Neither, Somewhat Unpleasant, Very Unpleasant
Eg. Non-slider Rating Scale
Unlikely (1) (2) (3) (4) (5) (6) (7) Very Likely
5. Semantic Differential Scale (A rating scale that asks people to rate a product, company, brand, or any 'entity' within the frames of a multi-point rating option)
Eg. Ordering
Rank of brands according to reliability: 1-Most Reliable, 2-Next Most Reliable, and so on.
__Ford __BMW __Chrsyler __Chevrolet
Eg. Satisfaction Rating
Very Unsatisfied, Unsatisfied, Neutral, Satisfied, Very Unsatisfied
6. Likert Scale (Goes from complete agreement to a complete disagreement)
Eg. Guttman Scale
a. Evaluate an organization’s hierarchical structure
__I am willing to contribute towards the social causes supported by my organization.
__I am willing to work longer hours to complete the assigned task.
__I am willing to communicate better with my team members.
__I am willing to attend conferences and seminars
b. “On a scale of 0-10, how satisfied are you with the service of this airline?”
Eg. Bogardus Scale (varying degrees of closeness in people towards other members)
Eg. Strongly Agree, Agree, Neutral, Disagree, Strongly Disagree
Eg. Even Likert Scale (4-point, 8-point),
Odd Likert Scale (5-point, 7- point, 9-point)
RATIO
They are named plus ordered plus proportionate interval between variables plus can accommodate zero.
It bears all the characteristics of an interval scale, in addition to that, it can also accommodate the value of “zero” on any of its variables.
EXAMPLES:
1. Height
2. Weight
3. Distance
4. Area
Reference:
https://www.questionpro.com/blog/nominal-ordinal-interval-ratio/