I’ve written a Matlab function, which calculates the Cronbach’s alpha between some items and do the if item is deleted process. this function will automatically delete the item which increase the Cronbach’s alpha maximally. before entering in if item is deleted process it checks the initial Cronbach’s alpha. if the Cronbach’s alpha value was greater than 0.8. then the function will return a message that there is an excellent reliability and no item is required to be deleted.It continues the process until reaches to the situation that no item could be deleted to increase the cronbach’s alpha more than what it is already or to the specified objective of the user.
The function is easy to use, the user only requires to enter the vector of the items, their labels and then run it. it will do the analysis fast and print the result in well arranged tables. using it makes the reliability analysis and scale parameters much more easier than using SPSS. while using SPSS is easy too. but due to automatically removing items and printing the results in the well numbered tables and specifying each step, makes the analysis and interpreting the results very easy.
here is a document file that shows the results of the reliability analysis by running this function to find the cronbach’s alpha.