Data were collected by survey with 21 Likert-type items. Each item allowed respondents to rate the frequency of performing specified “green” activities. Environmental experts combined the items into 3 scales (Most Convenient, Most Economical, and Most Environmentally Beneficial). All items use a 5 point scale which has the ordered options: Always, Regularly, Sometimes, Rarely, and Never.
We don’t have access to the survey instrument but I assume each item looked something like:
How often do you remove Roof Racks when not needed?
|value||Survey options||Definition (American Heritage® Dictionary)||Value (based on Definition)|
|1||Always||At all times, invariably||1|
|2||Regularly||Customary, usual, or normal||3|
|3||Sometimes||Now and then; from time to time; occasionally||2|
|4||Rarely||Not often; infrequently||4.5|
|5||Never||Not ever; on no occasion; at no time||5|
The wording violates three Likert item best practices.
|Symmetric||Is Sometimes the midpoint between Always and Never?|
|Equidistant||Is the difference between Always and Regularly the same as the difference between Rarely and Never?|
|Extremes||Some responders shy away from selecting absolutes (Always, Never). Using extremes tends to make the 5 point scale more like a 3 point scale.|
Based on the wording, the 6 inch rule used in the survey has:
- the ends chopped off,
- 2 and 3 swapped, and
- 4 close to 5.
While these problems may not invalidate the data, the poor choice of scale words will add noise to the measurements. This is unfortunate, especially in studies like this with small sample sizes.