Data Types: Nominal, Ordinal, Interval, Ratio

Nominal data are categories without a natural order or ranking (e.g., blood type, gender). Blood pressure levels are not nominal as they have a natural order. Ordinal data involves categories with a natural order but without a fixed interval between categories. Stages of disease progression are a good example of ordinal data. Interval data are numerical and have a meaningful order with equal intervals between values, but no true zero point (e.g., temperature in Celsius or Fahrenheit). Ages are typically considered ratio data because they have a meaningful zero point (age 0). Ratio data are similar to interval data but have a true zero point, allowing for statements of multiplicity. Number of times exercised per week is an example of ratio data because it has a true zero point (not exercising at all). Temperature in Celsius or Fahrenheit: The intervals between degrees are consistent, but there is no true zero point (0°C or 0°F does not mean the absence of temperature). Calendar Years: Years have consistent intervals (e.g., the time between 1990 and 2000 is the same as between 2000 and 2010), but there is no absolute zero year. IQ Scores: The scoring system for IQ tests is designed so that the intervals between scores are consistent, but there is no zero point that signifies the absence of intelligence. SAT Scores: The scores on standardized tests like the SAT are interval data because the intervals between points are equal, but the test doesn’t have a true zero point indicating the absence of knowledge. Time of Day (on a 12-hour or 24-hour clock): The intervals between hours, minutes, and seconds are consistent, but there is no true zero point (midnight or 12:00 doesn’t mean the absence of time). Elevation Above Sea Level: Elevation measurements have consistent intervals, but the zero point (sea level) is arbitrary and does not represent the absence of elevation. Interval data is characterized by equal intervals between values but lacks a true, meaningful zero point. This means that you can’t make statements about how many times greater one value is compared to another, which you can do with ratio data. In a study examining the effectiveness of a new medication, researchers collect various types of data from participants. Which of the following correctly identifies the type of data and provides an example of that data type? A. Nominal Data: Blood pressure levels of the participants. B. Ordinal Data: Stages of disease progression (e.g., Stage 1, Stage 2, Stage 3). C. Interval Data: Participants’ ages. D. Ratio Data: Number of times participants exercised per week.