Nominal data usually describes qualitative information. This essentially means that the information can be categorized or "named," hence the term "nominal." A common example of nominal data is gender. The classification for male (1) or female (2) can be used to describe participants in a study.
Ordinal data is essentially one step up from nominal. In fact, it is very similar to nominal data, but the information usually follows some type of ranking "order," hence the term "ordinal." An example would be ranking frozen pizzas - poor, fair, good, excellent.
Interval data is another level up on the list and is used to only describe quantitative information. This allows us to begin using mathematical operations to analyze the data. Statistics texts will often use temperature measurements as an example for interval data.
Ratio data is the final level of measurement scales. This type of data allows us to compare relative values using a true zero point. An example of ratio would be weight (as in the weight loss example from last week.)
Provide additional examples for each category of data