A researcher seeks to test the hypothesis that gender and aggression are related such that men are more aggressive than women. Gender is a categorical variable, and aggression is a numeric variable, so a correlation coefficient cannot be used to test the hypothesis. Instead, the mean aggression of the two groups, men and women are compared. This hypothesis would be stated in statistical terms, and notated, as follows: Null Hypothesis: the mean aggression score of men (m) equals the mean aggression score of women (w), H0: m = w Research Hypothesis: the mean aggression scores differ in men and women, H1: M m M w (non-directional) or Research Hypothesis: the mean aggression scores are higher in men than in women, H1: M m > M w (directional) Legend: represents the mean score in the population, M represents the mean score in the sample Previous research supports the directional hypothesis above, otherwise, it would reflect bias, so it can be justified. Similarly, the directional hypothesis that women are more aggressive than men would be biased, unless justified by past research. Never use the data you will use to test the hypothesis to justify the hypothesis (this is considered fraud), only use past research findings to justify the proposed hypotheses. The above hypotheses meet all the criteria: They state an expected relationship between two variables, gender and aggression