Westat Research Analyst interview questions

An HR rep contacted me about a month after I applied. She went over a few questions with me such as salary requirement and possible starting dates. She also asked me to send her a writing sample. A couple of days later she called to set up an on-site interview with some people from the department I would be working in. The interview lasted several hours. My initial meeting was with the HR woman I spoke to on the phone. She went over an extensive benefits guide and gave me some other materials about Westat. Then she walked me across the campus to meet with the research staff. The first panel interview consisted of 3 department heads. They claimed they were very eager to hire someone and wanted someone to start as soon as possible. They asked mostly 'big picture' questions about my overall experience. I then had two more panel interviews; each panel consisted of 3 research staff of all levels. They asked more detailed questions about my experiences as a researcher, but some of them also seemed bored - like this was just something they had to be doing. None of the interviews asked any outlandish questions or questions that I could not answer or that made me uncomfortable. In total I was at Westat for about 3 hours. HR said they would contact me the following week. I got a call the next week and was told they were still conducting interviews. I never heard from HR again, but I did receive an auto-generated email about 3 weeks later indicating that they had decided not to fill the position.