The most widely used method in the United States is based on the work of John E. Exner. In the Exner system, responses are scored with reference to their level of vagueness or synthesis of multiple images in the blot, the location of the response, which of a variety of determinants is used to produce the response (i.e., what makes the inkblot look like what it is said to resemble), the form quality of the response (to what extent a response is faithful to how the actual inkblot looks), the contents of the response (what the respondent actually sees in the blot), the degree of mental organizing activity that is involved in producing the response, and any illogical, incongruous, or incoherent aspects of responses.
Using the scores for these categories, the examiner then performs a series of mathematical calculations producing a structural summary of the test data. The results of the structural summary are interpreted using existing empirical research data on personality characteristics that have been demonstrated to be associated with different kinds of responses. Both the calculations of scores and the interpretation are often done electronically.
We, on the other hand, dispense with all that technical and pseudo-scientific mumbo-jumo, and simply give you some random answers. Many people claim that these are every bit as good as the "real" Rorschach answers determined by some highly paid, fancy-pants clinician or psychologist with an actual degree.