Module 1: Organizing Data – The Frequency Distribution
This main focus of this module is to teach you how to create a frequency distribution from raw data. The information in
this module corresponds to Chapter 2 in the text.
We’ll start with the following table of raw data:, which we’ll call Table 2.1
Example 1 -- Table 2.1
1.6
2.1
4.2
8.6
9.6
1.5
2.7
4.6
10.0
10.4
1.2
2.3
5.2
10.5
11.8
1.4
2.5
5.4
10.6
12.3
1.6
2.8
6.1
10.8
11.8
1.2
2.9
6.5
10.3
12.5
1.6
2.8
7.6
9.6
12.4
1.6
2.9
8.3
9.1
11.8

Module 1: Organizing Data – The Frequency Distribution
One of the biggest problems with any study is the amount and quality of data.
It’s therefore useful to have some kind of framework or method to reduce and summarize the raw data.
This allows the researcher to have the data in a format from which preliminary conclusions can be drawn.
The Frequency Distribution
A frequency distribution is the most common mechanism for summarizing raw data.
Basically, a frequency distribution is a technique for converting raw data into grouped data
2 Definitions:
Raw Data
: Information that hasn’t been summarized in any way.
Grouped Data
: Data that has been organized into a frequency distribution

Module 1: Organizing Data – The Frequency Distribution
There is a very specific process to convert this raw data into a frequency distribution.
The process involves 8 steps:
Step 1: Find the range
Step 2: Decide how many classes the data will be grouped into.
Step 3: Determine the width (w) of the class intervals.
Step 4: Select the endpoints (beginning point and end point) of each class interval.
Step 5: Determine the frequency (F) in each class interval.
Step 6: Determine the midpoint (MP) of each class interval.
Step 7: Determine the relative frequency of each class interval.
Step 8: Determine the cumulative frequency of each class interval.
When this process is complete, the result is a table which is also known as the frequency distribution.
Using the data in table 2.1, we’ll walk through the eight steps to create a frequency distribution.

Module 1: Organizing Data – The Frequency Distribution
Step 1: Find the range
Range: The distance (or difference) between the highest and the lowest element in the data set.
Sometimes with small data sets, it is easy to identify the highest and lowest number in the data, but that is usually not the
case. Therefore, we need a method that works with any set of data, large and small.
The best method is to arrange the data into ascending order.
That is, lowest to highest.
By far the easiest way to do this is to enter the data into Excel and use the data sort command to put the data into
ascending order.
Thus we begin with this...
1.6
2.1
4.2
8.6
9.6
1.5
2.7
4.6
10.0
10.4
1.2
2.3
5.2
10.5
11.8
1.4
2.5
5.4
10.6
12.3
1.6
2.8
6.1
10.8
11.8
1.2
2.9
6.5
10.3
12.5
1.6
2.8
7.6
9.6
12.4
1.6
2.9
8.3
9.1
11.8

And end with this...
Now that the data has been put into ascending order, it’s easy to see that
the
lowest number is 1.2 and the highest number is 12.5.

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- Spring '14
- DebraACasto
- Frequency distribution, 2008 in film