A frequency distribution is a summary of how often different scores occur within a sample of scores.
Let’s take a closer look at what this means.
A frequency can be defined as how often something happens. For example, the number of dogs that people own in a neighborhood is a frequency.
A distribution refers to the pattern of these frequencies. A frequency distribution looks at how frequently certain things happen within a sample of values.
In our example above, you might do a survey of your neighborhood to see how many dogs each household owns.
Let’s say you obtain the following set of scores from your sample:
1, 0, 1, 4, 1, 2, 0, 3, 0 2, 1, 1, 2, 0, 1, 1, 3
The first step in turning this into a frequency distribution is to create a table. Label one column the items you are counting, in this case the number of dogs in households in your neighborhood.
Next, create a column where you can tally the responses. Place a line for each instance the number occurs.
Finally, total your tallies and add the final number to a third column.
Number of Dogs in Household | Tally | Frequency |
0 | |||| | 4 |
1 | ||||| || | 7 |
2 | ||| | 3 |
3 | || | 2 |
4 or more | | | 1 |
Using a frequency distribution, you can look for patterns in the data. Looking at the table above you can quickly see that out of the 17 households surveyed, 7 families had one dog while 4 families did not have a dog.
Another Example of a Frequency Distribution
For example, let’s suppose that you are collecting data on how many hours of sleep college students get each night.
After conducting a survey of 30 of your classmates, you are left with the following set of scores:
7, 5, 8, 9, 4, 10, 7, 9, 9, 6, 5, 11, 6, 5, 9, 9, 8, 6, 9, 7, 9, 8, 4, 7, 8, 7, 6, 10, 4, 8
In order to make sense of this information, you need to find a way to organize the data. A frequency distribution is commonly used to categorize information so that it can be interpreted quickly in a visual way.
In our example above, the number of hours each week serves as the categories and the occurrences of each number are then tallied.
The above information could be presented in a table:
Hours of Sleep | Tally | Frequency |
4 | ||| | 3 |
5 | ||| | 3 |
6 | |||| | 4 |
7 | ||||| | 5 |
8 | ||||| | 5 |
9 | ||||| | | 7 |
10 | || | 2 |
11 | | | 1 |
Looking at the table, you can quickly see that 7 people reported sleeping sleeping for 9 hours while only 3 people reported sleeping for 4 hours.
How Are Frequency Distributions Displayed?
Using the information from a frequency distribution, researchers can then calculate the mean, median, mode, range and standard deviation. Frequency distributions are often displayed in a table format (as you can see in the example found below), but they can also be presented graphically using a histogram.
More Psychology Definitions: The Psychology Dictionary