[R] reliability, scale scores in the psych package

[Ista Zahn]

<snip>
> Second question: I spent some time with the psych package trying to
> figure out how to use the score.items() function, and it's become
> clear to me that I don't understand what it's doing. I assumed that
> setting a key equal to -1 would result in the item being reverse
> scored, but I get weird results, as shown below. When I try to reverse
> score (by setting a value of -1 in the key), I get scale scores that
> don't add up (e.g., the mean score is reported as being larger than
> the maximum item score). How is the score.items() function intended to
> be used? Do I need to reverse score items before using score.items()?

I did it again--it seems like I always figure out the answer just
after I ask for help. The score.items() function needs to know the
maximum of the scale in order to reverse score. For some reason, the
maximum appears to be calculated from all the scores, not just scores
that have a 1 or a -1 in the key. On a hunch I set the max argument to
a vector of scale maxima, and it worked. I'm still interested in
responses to question 1 though.

Thanks again,
Ista

<snip>