Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Statistical inference is the process of making conclusions using data that is subject to random variation, for example, observational errors or sampling variation. More substantially, the terms statistical inference, statistical induction and inferential statistics are used to describe systems of procedures which can be used to draw conclusions from every dataset arising from every system affected by random variation. The requirements of such a system of procedures for inference and induction are, initially, that it should produce reasonable answers when applied to simple well-defined situations and that it should be general enough to be applied across a range of situations. The outcome of statistical inference may be an answer to the question "what should be done next?", where this might be a decision about making further experiments or surveys, or about drawing a final conclusion before implementing some organizational or governmental policy.