I noticed in the chapters I'm working on that often various things, such as
all the items on the various pages of the Options dialog, it refers to
"selecting" an option. In one place it was more noticeable in the user was
directed to "select" something in the dialog.
In that case, the terminology is clearly wrong. Selecting is not the same
as operating on the widget. Selecting directs the attention to it, and
another operation may then be performed, such as toggling a check box.
I suppose in some context where the option itself is referred to in an
imperative sense, saying the option is selected is OK and in fact I didn't
notice initially. But you'd have to be careful about the wording of the
sentence: are you being imperative or directing the user's action? It's
more consistent and easier to just use a word that always works. To that
end, I'm changing whatever descriptive phrase was used to "enabled"
(antonym: "disabled"). That works for any type of control (check box, radio
box, combo-box).
I'm also trying to be more careful about wording things to reflect the
desired state, rather than the action. I.e. clicking on an option doesn't
necessarily enable it: it will toggle it, and you shouldn't click on it
unless it was off before. So don't (just) direct the user to click on
something to achieve an effect. Rather, the effect occurs when the option
is enabled. And of course this is the very case in which merely selecting
it doesn't do anything other than make the gui draw a selection rectangle
around that item.