Should I be credited for my programming contribution to a dissertation? A psychology PhD candidate has been doing research on students (sorry i don't think I can be any more specific than this).  They needed someone to develop a application that gathers metrics about each student and then reports back to a central database. The PhD candidate then accesses the database and runs various metrics on the data to try to uncover patterns.  I was the person chosen to code the application.  I put about 100 hours into building this software application and I was compensated fairly for my effort.  Since then I have done regular maintenance and updates on the software/database and I continue to get compensated. Other than the software aspect, I really know nothing more about their research or dissertation.

My question is: Is there any expectation that I should be credited in the dissertation for my work on the software?  Without my software, the various studies simply would never have happened because there currently doesn't exist any commercial software that does what was needed.  On the flip side, I didn't actually help with the research, i had no say in the design or manner of the studies and was essentially uninvolved with anything that did not directly deal with the code.  

The reason I am asking this question is mostly to see if I can use my work on this project in future resumes or CV's and actually list myself as a contributor on the project. In my normal life, I am not an academic or involved with any sort of academia other than this one incident so I am pretty clueless when it comes to this type of stuff.
You did work for hire for a research group. Since you say you were strictly involved in developing the tool and not in the research, authorship of subsequent publications is not to be expected. An acknowledgment in the thesis would be appropriate but it would have very little weight in a CV, inside or outside academia.

At any rate, you can definitely list your contribution to this project in your CV regardless of which kind of acknowledgment you might get. In fact having delivered a working software and gotten paid for it will be much more helpful than any kind of authorship/acknowledgments when applying for jobs outside academia.