Scales of Measurement - Nominal, Ordinal, Interval, Ratio (Part 1) - Introductory Statistics

This video reviews the scales of measurement covered in introductory statistics: nominal, ordinal, interval, and ratio (Part 1 of 2).

Scales of Measurement
Nominal, Ordinal, Interval, Ratio

Subscribe today!

Video Transcript:
In this video we'll take a look at what are known as the scales of measurement. OK first of all measurement can be defined as the process of applying numbers to objects according to a set of rules. So when we measure something we apply numbers or we give numbers to something and this something is just generically an object or objects so we're assigning numbers to some thing or things and when we do that we follow some sort of rules. Now in terms of introductory statistics textbooks there are four scales of measurement nominal, ordinal, interval, and ratio. We'll take a look at each of these in turn and take a look at some examples as well, as the examples really help to differentiate between these four scales. First we'll take a look at nominal. Now in a nominal scale of measurement we assign numbers to objects where the different numbers indicate different objects. The numbers have no real meaning other than differentiating between objects. So as an example a very common variable in statistical analyses is gender where in this example all males get a 1 and all females get a 2. Now the reason why this is nominal is because we could have just as easily assigned females a 1 and males a 2 or we could have assigned females 500 and males 650. It doesn't matter what number we come up with as long as all males get the same number, 1 in this example, and all females get the same number, 2. It doesn't mean that because females have a higher number that they're better than males or males are worse than females or vice versa or anything like that. All it does is it differentiates between our two groups. And that's a classic nominal example. Another one is baseball uniform numbers. Now the number that a player has on their uniform in baseball it provides no insight into the player's position or anything like that it just simply differentiates between players. So if someone has the number 23 on their back and someone has the number 25 it doesn't mean that the person who has 25 is better, has a higher average, hits more home runs, or anything like that it just means they're not the same playeras number 23. So in this example its nominal once again because the number just simply differentiates between objects. Now just as a side note in all sports it's not the same like in football for example different sequences of numbers typically go towards different positions. Like linebackers will have numbers that are different than quarterbacks and so forth but that's not the case in baseball. So in baseball whatever the number is it provides typically no insight into what position he plays. OK next we have ordinal and for ordinal we assign numbers to objects just like nominal but here the numbers also have meaningful order. So for example the place someone finishes in a race first, second, third, and so on. If we know the place that they finished we know how they did relative to others. So for example the first place person did better than second, second did better than third, and so on of course right that's obvious but that number that they're assigned one, two, or three indicates how they finished in a race so it indicates order and same thing with the place finished in an election first, second, third, fourth we know exactly how they did in relation to the others the person who finished in third place did better than someone who finished in fifth let's say if there are that many people, first did better than third and so on. So the number for ordinal once again indicates placement or order so we can rank people with ordinal data. OK next we have interval. In interval numbers have order just like ordinal so you can see here how these scales of measurement build on one another but in addition to ordinal, interval also has equal intervals between adjacent categories and I'll show you what I mean here with an example. So if we take temperature in degrees Fahrenheit the difference between 78 degrees and 79 degrees or that one degree difference is the same as the difference between 45 degrees and 46 degrees. One degree difference once again. So anywhere along that scale up and down the Fahrenheit scale that one degree difference means the same thing all up and down that scale. OK so if we take eight degrees versus nine degrees the difference there is one degree once again. That's a classic interval scale right there with those differences are meaningful and we'll contrast this with ordinal in just a few moments but finally before we do let's take a look at ratio.

[devinsturgeon]

YouTube needs its own college. My university stats professor spent most of class teaching this and it made no sense. This video explains it perfectly in 5 minutes.

[bvoy]

@01:46 Nominal begins
@03:49 Ordinal begins
@04:49 interval begins
Part 2 has ratio

[calebchuks]

This is One of the best explanation on scale by far, from my teaching experience *what shows you author an understanding of a subject matter is creating your personalized example and a general one that is relatable* Good job sir.

[blank]

My college professor spent the entire class period explaining this concept, along with complaining and rambling her opinions... this video was EXTREMELY helpful. I understood first watch. Thank you sm

[adriantaylor]

THANK YOU! THANK YOU! THANK YOU! Finally, an explanation that makes sense. Your use of sports illustrations unlocked my understanding for the level of measurement. I cannot tell you how excited that this concept now sticks in this 42-year-old brain.

[villamodel]

This is great. Super helpful. I personally appreciate the time you took to provide examples.

[hermajesty]

Your voice just has a great tone. Perfect for a teacher. Thank you

[Ureyeuh]

I have been referencing this channel for years. This is insanely good, quick, well communicated information.

[degsvlogs]

Please do not stop from helping people, like me.
I deeply appreciate the information you shared!

[Pwnyable]

When watching this, increase the speed to 1.25x

[phortunateejimone]

The 51 people and 17 people who have a thumb down to this video are morons. It can't get any better. Good job. One of the best...

[medisheen]

Thanks for this! the baseball uniform example was really helpful!

[antaozzaenha]

I'm going to have my final after 3 hours and it's helping me alot....thank you

[nouf]

i would love to say that you made this ssssoooo easy for me to understand THANKS

[getsetgophysio]

It's 6 years ago video and now it is very much useful for me... Perfect speed

[jeniferkpundeh]

Best online lecture ever on scales of measurement

[samriddhikafle]

The video explains in detail about the five scales of measurement. It explains by assigning values on objects and diffrentiate between them

[alihasnain]

hey sir greeting you from Pakistan Sir your video is superb and really helpful

[michaelenorr]

That was lovely! I needed those examples :)

[priscillaprakash]

Wonderful explanation with
Striking examples.