The Short Dark Triad (SD3) is a 27-item measure of Machiavellianism, narcissism, and psychopathy โ nine items per trait, rated on a 5-point scale from disagree strongly to agree strongly, with five items reverse-scored. The most common write-up mistake is treating it like it produces a single "dark triad score." It doesn't. Report three subscale scores.
The reliability line
Cronbach's alpha for the three SD3 subscales runs ฮฑ = .72โ.77 in the original validation (Jones & Paulhus, 2014) โ lower than a 44-item personality inventory, but expected for nine-item subscales measuring a narrow trait. Report each subscale's alpha, not one pooled number.
One thing worth a sentence in your write-up: the three subscales correlate with each other (roughly r = .30โ.50 in the validation sample). They're related but distinct constructs, not one factor split three ways โ say that if you're justifying analyzing them separately.
A sample paragraph
Dark personality traits were assessed using the Short Dark Triad (SD3; Jones & Paulhus, 2014), a 27-item measure of Machiavellianism, narcissism, and psychopathy (nine items per subscale, five reverse-scored), rated on a 5-point scale from disagree strongly to agree strongly. Subscale scores were computed as the mean of their constituent items. Internal consistency in the original validation ranged from ฮฑ = .72 to .77 across the three subscales.
Swap in your own sample's alphas once calculated, and note if any subscale fell notably below the original range โ that's worth flagging, not hiding.
Reference: Jones, D. N., & Paulhus, D. L. (2014). Introducing the Short Dark Triad (SD3): A brief measure of dark personality traits. Assessment, 21(1), 28โ41. https://doi.org/10.1177/1073191113514105
Folio's SD3 scale page has the full item list, scoring key, and citation formatted in your style โ useful for double-checking your own coding before you report it.