1.01 Levels Of Measurement Flashcards
Nominal variables level
Categorical
Difference| Order | Similar intervals | Meaningful ZERO point |
The most simple level of measurement is the nominal level. A nominal variable is made up of various categories that differ from each other. There is no order, however. This means that it’s not possible to argue that one category is better or worse, or more, or less than another. An example is the nationality of the football players. The various categories, for instance Spanish, French, or Mexican differ from each other, but there is no ranking order.
Another example is the gender of the football players or the city the football teams come from.
Ordinal variables level
Categorical
Difference | Order | Similar intervals | Meaningful ZERO point |
The second level of measurement is the ordinal level. There is not only the difference between the categories of the variable, there is also an order. And example is the order in a football competition. You know who is the winner. You know who came second, and third, etc., etc. However, by looking at the order, you don’t know anything about the differences between the categories. You don’t know, for example, how much the number one was better than the number two.
Interval variables level
Quantitative
Difference | Order | Similar intervals | Meaningful ZERO point |
The next level of measurement is the interval level. With interval variables, we have different categories and an order, but also similar intervals between the categories.
An example is the age of a football player. We can say that a player of 18 years old differs from a player of 16 years old, in terms of his or her age. In addition, we can say that this player is older. But we can also say that in terms of age, the difference between a 18 year old player and a 16 year old player, is similar to the difference between a 14 year old player and a 12 year old player.
Ratio variables level
Quantitative
Difference | Order | Similar intervals | Meaningful ZERO point |
The final level of measurement is the ratio level. It is similar to the interval level but has, in addition, a meaningful zero point.
An example is a player’s body height, measured in centimeters. There are differences between the categories. There is an order, there are similar intervals, and we have a meaningful zero point.
A height of zero centimeters means that there is no height at all. Note that we cannot say that age has a meaningful zero point, because an age of zero does not mean that there is no age. Age therefore is an interval variable.
Categorical variables levels
Nominal level
- Differences
- Order
- Similar intervals
- Meaningful ZERO level
Ordinal level
- Differences
- Order
- Similar intervals
- Meaningful ZERO level
Quantitative variables levels
Interval level
- Differences
- Order
- Similar intervals
- Meaningful ZERO level
Ratio level
- Differences
- Order
- Similar intervals
- Meaningful ZERO level
Quantitative DISCRETE variables
A variable is discrete if it’s possible categories form a set of separate numbers.
For instance, the number of goals scored by a football player. A player can score, for instance, one goal or two goals, but not 1.21 goals
Quantitative CONTINUOUS variables
A variable is continuous if the possible values of the variable are form an interval.
An example is again, the height of a player. Someone can be 170 centimeters, 171 centimeters tall. But also for instance, 170.2461 centimeters tall.
We don’t have a set of separate numbers, but an infinite region of values.
Why is it so important to distinguish
these various levels of measurement?
Because the methods we employ to analyze data depend on the level on which the variables are measured!
