The Academic Motivation Scale — College version (AMS-C 28; Vallerand et al., 1992) measures seven motivational orientations rooted in self-determination theory: three types of intrinsic motivation, three of extrinsic motivation, and amotivation. That's 28 items, four per subscale, on a 7-point scale from does not correspond at all to corresponds exactly.
The reliability line — and why it isn't one number
Subscale alphas in the validation literature range from α = .62 to .86. That range matters: the low end (around .62) belongs to the Identified Regulation subscale specifically, which is a known soft spot for this instrument, not a sign something went wrong in your data collection. Report each subscale's alpha individually rather than a single averaged figure — collapsing seven different numbers into one range hides exactly the information a reader needs to judge which of your seven scores to trust most.
A sample paragraph
Academic motivation was measured using the Academic Motivation Scale — College version (AMS-C 28; Vallerand et al., 1992), a 28-item instrument assessing seven motivational orientations — three intrinsic (to know, toward accomplishment, to experience stimulation), three extrinsic (external, introjected, and identified regulation), and amotivation — rooted in self-determination theory. Each subscale comprises four items rated on a 7-point scale from does not correspond at all to corresponds exactly, with subscale scores computed as the item mean. Internal consistency across subscales in the original validation ranged from α = .62 to .86, with the Identified Regulation subscale showing the lowest reliability.
If your own Identified Regulation alpha also lands on the low side, that's consistent with prior findings — no need to over-explain it, just report it alongside the others.
Reference: Vallerand, R. J., Pelletier, L. G., Blais, M. R., Brière, N. M., Senécal, C., & Vallières, É. F. (1992). The Academic Motivation Scale: A measure of intrinsic, extrinsic, and amotivation in education. Educational and Psychological Measurement, 52(4), 1003–1017.
Folio's AMS-C 28 scale page breaks out all seven subscales with their item sets — useful for confirming which four items belong to which orientation before you score.