If you find a pre-existing instrument that will be useful to measure a key variable in your study, there are two ways that the instrument can be used in your study. The first is to take the instrument nearly verbatim, which is called adopting the instrument. On the other hand, you can significantly alter the instrument, which is called adapting.
In general, adopting (using verbatim) is preferable to adapting for a few reasons. First, when the instrument is adopted, then the reliability and validity research studies that have been conducted on that instrument can be applied to your study, so you do not have to collect validity evidence. However, when an instrument has been adapted, then it has been significantly changed so the reliability and validity evidence will not apply to your study. Second, adopting an instrument links your study to all other research studies that have used the same instrument. Finally, adopting the instrument saves you time and energy in making significant changes.
However, sometimes an instrument is not appropriate for the unique participants in your study and therefore should not be adopted. Some examples of when an instrument must be adapted may include:
Whether adopting or adapting an instrument, it is always courteous to email the authors of the instrument to ask permission. (Their email address can typically be found on either the first page of the research study in a footnote, or at the end of the body of the paper, just before the References.) Simply state your institutional affiliation, the purpose of your study, and ask if it would be acceptable for you to use their instrument in your study. The authors will rarely deny your request, but it is a polite academic courtesy to let another researcher be aware of how their instrument is being used around the world.
Adopting an instrument is quite simple and requires very little effort. Even when an instrument is adopted, though, there still might be a few modifications that are necessary. For example, the Intrinsic Motivation Inventory that measures intrinsic motivation, which can be found here, needs to be slightly modified to reflect the specific situation that the researcher is interested in. Intrinsic motivation is not a general variable, but is directed at a specific activity: intrinsic motivation in maths, intrinsic motivation in social studies, intrinsic motivation in playing sport, intrinsic motivation in reading a book, etc. Therefore, the items on the Intrinsic Motivation inventory should reference that specific activity. For example, an item on the Intrinsic Motivation Inventory reads, "I enjoyed doing this activity very much." How will the participants know what "this activity" is? Therefore, it is best for the researcher to modify the item to read "I enjoyed the maths computer program very much." Note that the substance of the item was not changed, only the reference of "this activity."
Even though adopting an instrument requires little effort on behalf of the researcher, the questionnaire still must be appropriately designed so it is important that you read about Developing a Questionnaire .
When an instrument is adopted, it is important to appropriately describe the instrument in the Instruments section of Chapter 3. In the description, include
Here is an example portion of the Instruments section from an instrument that was adopted:
Positive and negative affect were assessed using the Positive and Negative Affect Scale (PANAS; Watson, Clark, & Tellegren, 1988)...Watson and colleagues report reliability coefficient alphas as .89 for positive and .85 for negative affect. Validity evidence for the instrument as a measure of state affect was found by correlating the instrument with situations that should influence positive and negative affect. Positive affect has been found to be related to social activity and negative affect has been found to be related to fluctuations in stress (Watson et al., 1988). The PANAS has been used to assess affect in other studies with SDT (e.g., Elliot and Sheldon, 1999; Sheldon & Kasser, 2001; Sheldon, Ryan, Deci, & Kasser, 2004).
Adapting an instrument requires more substantial changes than adopting an instrument. In this situation, the researcher follows the general design of another instrument but adds items, removes items, and/or substantially changes the content of each item. Because adapting an instrument is similar to developing a new instrument, it is important that a researcher understands the key principles of developing an instrument which will be described in the next step.
When adapting an instrument, the researcher should report the same information in the Instruments section as when adopting the instrument, but should also include what changes were made to the instrument and why. Below is a sample description of an instrument that was adapted in Korb (2009).
This study adapted the Factors Influencing Teaching Choice (FIT-Choice) scale. This instrument was developed by Watt and Richardson (2007). Validity evidence was provided by factor analysis and the longitudinal relationship of the factors influencing teaching to subsequent engagement in the teaching profession. The purpose of the FIT-Choice is to determine the factors that preservice teachers identify as being most influential in their choice of the teaching profession. The FIT-Choice scale was only slightly modified to fit the Nigerian context. All factors were identical to the original FIT-Choice instrument except for two. Watt and Richardson identified a job transferability factor that included items such as "Teaching will be a useful job for me to have when traveling." This factor was judged as not applicable to Nigerian pre-service teachers. Additionally, an exploitation factor was added to the instrument to represent choosing teaching as a lazy, easy career with items such as "Teaching will allow me to work other jobs," "Teaching will allow me to collect a salary by doing little work," and "When teaching, I can use the students for gaining money."
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Copyright 2012, Katrina A. Korb, All Rights Reserved
Copyright 2012, Katrina A. Korb, All Rights Reserved