Reliability: Cronbach alpha and KR20
Message posted by Su Luan on August 12, 2000 at 12:00 AM (ET)

I came with up with an instrument to measure teachers' IT preparedness which comprises skills, knowledge and attitudes. My data for skills and knowledge are dichotomous (right and wrong) while attitudes is measured in a 5 point
likert scale form. I used KR20 for skills and knowledge and cronbach's alpha
for attitudes. So I have 3 different values for reliability for each
subdomain (skills, knowledge and attitudes). Now, I would like to find out the overall reliability for the instrument(can it be done?). How do I measure that since the data would be a combination of dichotomous data and likert scale data?
Thanks