Any experience and suggestion on response option when measuring «belief strength» and «outcome evaluation» within the TPB framework?
(a) unipolar scoring (from 1 to 7)
or
(b) bipolar scoring (-3 to + 3)
or
(c) a combination of both?
Ajzen (1991) advocates for the use of bipolar scaling when it comes to belief strenght (p. 192-194). He argues that from a measurement perspective, either unipolar or bipolar measures can be used. However, he shows that the correlations with the global attitude is higher when using bipolar scales of belief strenght. This said, others (e..g. Schwartz, 1999 attached) show that people may interpret the questions differnetly depending on which scale (uni or bi) that are used (see p. 95-96).
Hope this helps
Ajzen, I. (1991). The theory of planned behavior. Organizational Behavior and Decision Processes, 50, 179-211.
Thank you for the answer.
However, using bipolar measures may report some problems. Imagine the belief that "running 2 miles daily may led to injuries".
Participant A may think that this is extremely likely to ocur (so he choose +3, showing a bad attitude toward running 2 miles daily), but for him, being injured is irrelevant (so he choose 0), being the total score 0 (due to the multiplication by 0)
On the other hand, participant B ay think that this is extremely unlikely to ocur (so he choose -3, showing a good attitude toward running 2 miles daily", and also belief that being injured is irrelevant (so he choose also 0), being the total score 0.
Both participants will have the same total score (0), that will show no contribution to the attitude (although they have different attitude toward that behavior).
One possible solution may be to use a bipolar (-3,+3 for beliefs strength) and a unipolar one (1-7; for outcome valuation)?
- Badges
- Science topic
- Similar topics
- Social Psychology
- Attitude