There are several equally acceptable ways to write purpose statements for quantitative studies. This post will share some suggestion for getting started

Ideas for Writing Quantitative Purpose Statements

A well-written quantitative purpose statement contains the following elements

• identified variables
• the relationship among the variables
• the participants
• the site of the research

Here is an example

The purpose of this study is to determine the strength of the relationship between height to weight among undergrad students in Thailand.

Here is a breakdown of the elements of the purpose statement above.

• identified variables [Height and Weight]
• the relationship among the variables [Height is the independent variable weight is the dependent variable]
• the participants [undergrad students]
• the site of the research [Thailand]

Here are some additional tips

• Try to write purpose statements in one sentence
• Start with the phrase “the purpose of this study” it’s a clue to readers
• Specify all variables in the study such as independent, dependent, mediating etc.
• The order variables are introduced is the following
  1. Independent
  2. Dependent
  3. Mediating or control
• Variables are used for relationships between two or more, compare groups, or description
• If you are testing a theory, comparing groups, or describing something, state this in the purpose statement

Below is an example, the characteristics of a purpose statement are underlined and in parentheses.

The purpose of this study is to test the theory of planned behavior (the theory) by relating social support (independent variable)  to college intention  to dropout (independent variable)  for undergrad students (participants) in Thailand (research site)

Comparison is another common form of research. Below is a purpose statement that focuses on comparing groups. the characteristics of a purpose statement are underlined and in parentheses.

The purpose of this study music choice(independent variable) of classical (group 1), contemporary (group 2),  and no music(group 3) in terms of its influence on academic performance (dependent variable) for undergrad students (participants) in Thailand (research site)

In the above example, music choice is the independent variable that is hypothesized to influence academic performance. Three types of treatment are employed classical, contemporary, and no music. The goal is to see if there is a difference in the means of academic performance at the completion of the study.

Conclusion

Purpose statements for quantitative studies are important as they lay the foundation for a study. A good statement tells a reader what to expect for the rest of the study. For this reason, researchers need to be careful and think of the purpose statement with care.