Estadística Descriptiva - Tipos de variables según su escala
Types of Variables According to Their Scale
Overview of Variable Types
- The video introduces the classification of variables into two main groups: quantitative and qualitative.
- Quantitative variables can be expressed numerically, such as weight or money, while qualitative variables express qualities like gender, color, or education level.
Qualitative Variables
- Qualitative variables are further divided into nominal and ordinal categories.
- Nominal variables do not allow for ordering; for example, classifying people by eye color does not establish a hierarchy.
- An example is presented where individuals can be arranged by gender without a definitive order.
Ordinal Variables
- Ordinal variables have a clear order; for instance, educational levels can be ranked from no education to higher degrees (e.g., master's or doctorate).
- Different presentations may reorder individuals based on their educational attainment but maintain the inherent ranking structure.
Quantitative Variables
- Quantitative variables are classified into two types: scale (or ratio) and those that cannot undergo calculations.
- Scale variables allow for calculations like average age or average money in bank accounts.
Limitations of Rankings
- Non-calculable quantitative data primarily involves rankings; calculating an average position among ranks lacks meaning.
- The difference between ranks (e.g., 1st vs. 3rd place versus 1500th place) illustrates that not all positions hold equal significance in terms of performance outcomes.
Summary of Variable Classification
- The classification concludes with three types:
- Nominal variables expressing qualities without order,
- Ordinal variables with an established order,