| Data: The facts or numbers that describe something.
Types of Data
There are three different kinds of data:
- Categorical, such as a person's gender, race, or religion
- Count, such as the number of televisions in a person's house, number of packs
of cigarettes smoked per day, number of visits to the doctor per year.
- Measurement, such as a person's test score, height, weight.
If data can be represented by one and only one
category (e.g., a person's gender) it is called qualitative data.
Categorical Data is
Quantitative data are data values that can be measured on a numerical
Counts and measurements are
If a data set included the following points, 32,
15, 1, 27, 16, 22, 8, and 12, the range of the data would be 32 - 1 =
The first step in collecting data is to specify
variable names for data you are
interested in. The values of the variable are
the data that has been collected.
For each case the variable has a certain value.
For example, if you had a variable for the person's gender, the variable name
might be gender and the values could be M for male and F for female. If the
study was interested in the age of a person, there could be a variable named age
which had numbers (ages) for the values.
the peanut butter jar at the right to see Peanut Butter Data which will be used
throughout this page.
|In statistical packages
or spreadsheets on the computer, data is
usually arranged in tables. Each column
contains the values for one variable. The rows contain all the data for a single
How do we get data?
There are two ways we can collect data: through
observation and through experiments.
- We can record things that we observe in the world around
- We can record measurements as the result of an