The whole point of statistics is to quantify uncertainty. 'Statistics means never having to say you are certain.' If a statistical conclusion ever seems certain, you probably are misunderstanding something. Statistical conclusions are always presented in terms of probability. Statistical rigor is needed to make valid conclusions from data. People frequently see patterns in random data and often jump to unwarranted conclusions. When thinking about data, intuition often leads us astray. The other meaning of 'intuitive' is “instinctive, or acting on what one feels to be true even without reason.” Using this definition, statistical reasoning is far from intuitive. One meaning is “easy to use and understand.” That was my goal when I wrote Intuitive Biostatistics. But the challenging and difficult aspects of statistics are all about reaching general conclusions from limited data. 'Descriptive statistics' simply describes data without reaching any general conclusions. The whole point of inferential statistics is to extrapolate from limited data to make a general conclusion. Statistics lets you make general conclusions from limited data. Here are the twelve most important concepts in statistical inference. When learning statistics, it is easy to get bogged down in the details, and lose track of the big picture. If you know twelve concepts about a given topic you will look like an expert to people who only know two or three.

Graphpad prism 5 statistics guide