After data has been collected and compiled, now the researcher would want to know if there is any excess risk or reduced risk in any particular study group or in relation to any particular exposure. The methods to be utilized for reaching such a conclusion needs proper understanding of Assessment of Risk and forms the content of discussion of Chapter 8. We have included both techniques used for assessing risk, direct as well as indirect. In the direct methods we have included risk ratio (or relative risk), risk difference (or attributable risk); and among the indirect methods we have included the relative odds (or odd’s ratio), the rate ratios and rate differences for exposure and disease.