Week 2: levels of measurement

3 parts of a concept

1. label
2. conceptual definition
3. operational definition

Label

way to refer to something (public opinion, media use, people)

 

Conceptual Definition

what is the verbal meaning attached to concept label?

sometimes the label is enough, you don't need it. (intelligence: quantitative, analytical, verbal)

 

Operational Definition

takes verbal meaning from conceptual definition and specifies the steps needed to measure/experience that concept. (develop steps for measuring conceptual definitions and devise a formula)

 

Operational definition should do a good job representing the conceptual definition, if it doesn't we aren't measuring what we thought we were

 

4 Levels of measurement

1. Nominal
2. Ordinal
3. Interval
4. Ratio

 

Nominal

• weakest form
• classifies people, things etc.
• label for a category
• refers to presence/absence of something
  • equivalence: everything in that category has to be equal
  • categories: exhausted and mutually exclusive 

Ordinal

• rank on some dimension but not specific (horse race w/ no stop watch: 1st, 2nd, 3rd)
• non specific measurements, you know the order but you do not know the distance between
  • has an order: any category can fall higher or lower to another
  • categories: exhausted and mutually exclusive 

Interval

• equal interval measurements 
• NO TRUE ZERO: when zero does not mean absence of the thing because you can go below it. (weather)

Ratio

• DOES have a true zero, [[must have everything stated in interval]] ——— speed, distance traveled

 

Why should you start at the highest level of measurement?

   you can start high and go low, but you cannot start low and go high

 

How will 4 levels of measurements be used?

   chi squared data ——

   pew data —— nominal/ordinal

   analysis of variants (calculating mean) —— interval/ratio