Hello, I am recently learning data analysis methods. The concept of “multiple regression” confuses me. There are so many factors that might influence the effects of independent variables on the dependent variable, then how can we determine which ones shall be included and others not?

Not to mention.

OK. Thanks!

Indeed it is impossible to rule out every confounding factor in data analysis in social work research. What we need to pay attention to is the most important ones to your interest and control other variables. For example, age and education may affect the DV, but you may treat them as control variables in your analysis if they are not of your interest.