Types of Statistical Methods
1. Mean and standard variation
2. Ordinary least squares regression and logistic regression
3. Mediation (or intervention) and moderation (or interaction)
4. Chi square (χ2 ) test
5. Null hypothesis and research hypothesis
6. Standard deviation
7. Unstandardized regression coefficient (B) and standardized regression coefficient (β)
8. Pearson’s r and Spearman’s rho
Discussion of when to use the statistical methods
1. The mean is a measure of central tendency used when the data distribution is continuous and symmetrical.
Standard variation is used to summarize continuous data, not categorical data, in accordance with the mean.
2. The ordinary least squares regression is used in estimating relationship between one or more independent variable and a dependent variable.
Logistic regression is used in estimating relationship between categorical independent variable and dichotomous dependent variable.
3. Mediators explain the how or why of a relationship between two other variables (typically well-established) and are often called intermediary variables because they also describe the mechanism by which an effect occurs. Mediation tests whether the effects of X (the independent variable) on Y (the dependent variable) operate through a third variable, M (the mediator)
A moderator analysis is used to determine whether the relationship between two variables depends on (is moderated by) the value of a third variable.
4. The Chi-Square statistic is commonly used for testing relationships between categorical variables. The null hypothesis of the Chi-Square test is that no relationship exists on the categorical variables in the population; they are independent.
5. The null hypothesis is useful because it can be checked to decide whether two measured phenomena have a relationship or not.
Research hypothesis is used when we are interested in testing a theory or an idea how things relates with one another.
6. The standard deviation, like the mean, is normally only appropriate when the continuous data is not significantly skewed or has outliers.
7. Unstandardized regression coefficient is used to make comparisons within the regression equation when just one measurement scale is in use.
Standardized regression coefficient is usually used to answer the question of which of the independent variables has a greater effect on the dependent variable in a multiple regression analysis.
8. Pearson's correlation is used only to determine whether there is a linear relationship between variables. It can be a positive or negative relationship, as long as it is significant.
Spearman correlation is often used to evaluate relationships involving ordinal variables.