Do the items on a scale hang together and measure one thing?
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# Cronbach's alpha - scale reliability library(psych) # Five agreeableness items from the bfi dataset items <- bfi[, c("A1", "A2", "A3", "A4", "A5")] # Cronbach's alpha (A1 is reverse-keyed) a <- alpha(items, check.keys = TRUE) a$total
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When to use it. Use it to assess a multi-item scale’s internal consistency; values above ~0.7 are usually acceptable. Remember to reverse-key negatively worded items.
Read Cronbach’s alpha in R.
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