This chapter deals with a number of important statistical terms, such as normal distribution, significance, probability and standard error. Before they enter the data, students first have to make, for their own use, a summary of the variables involved in the research and the values that these could have. When they have collected the research data and composed a coding scheme, students can enter the data in the computer. Students do so by typing theit data into the data editor, which appears on the screen when they start SPSS. Similarly, students have to check if the variables display sufficient variation. If there are very few men in their sample, it will be difficult for students to determine if a difference exists between men and women in, for example, the degree of their happiness. The chapter also presents an overview of the key concepts discussed in this book.