While many of us can think interviewing is a one-way street, the reality is that you are also judging your own reactions during an interview process. Listed below are a few things for you to pay attention to during the entire scope of the interview process, which will help you appropriately evaluate the job you're pursuing.
Clues from the Application Process
How has the organization handled the application process? For example, were you provided some type of notification that your resume was received? How and when were you contacted about scheduling an interview? Did you receive a follow-up email confirming the date, time, and location of the interview, or were you just provided that information over the phone? At this point, you have to determine if you feel like you were treated with respect, courtesy, and professionalism. So... how are they doing?
As part of your interview preparation, hopefully you read the organization's website and gained additional information about them, and perhaps the interviewers as well. If possible, see if you can connect with a current or past employee of the organization to ask him/her about his/her experience of working there. Take this information into consideration as you think about the open position.
Clues from the Interview
While you were waiting for your interview in the reception area, what interactions did you observe? Was the receptionist courteous and helpful? How did employees you could hear or see respond to incoming phone calls and coworker interactions? Were they simply "doing their jobs," or did they appear to be enjoying their work? Did employees seem happy and friendly? In this vein, perhaps there is an organization newsletter that can give you insight into the work culture. Remember the importance of the physical space: can you see yourself working in the area through which you walked? Did you see smiling faces? Positive group interactions? What did your observations tell you about the organization?
As you were answering questions during the interview, how did you feel about your interviewer(s)? Did you develop rapport quickly and easily, or did it take a lot of work?
Sit back and revisit the entire process to date. If something isn't feeling quite right, ask yourself what it is or why you may be feeling that way. Perhaps you need more information, which you can acquire by asking additional questions. On the other hand, depending on your particular reservations, you may simply need to acknowledge that this isn't the right position for you. Don't discount the power of prayer here, and remember to discuss any concerns you have with trusted family, friends, or mentors. While the decision ultimately comes down to you to make, others can be a great source of wisdom, and can keep you from remaining too much in your own head.