How do we know whether we use t-test, ANOVA, chi-square, correlation, or regression analysis?
Material in (parentheses) is sort of optional. For a newcomer, you can read this answer without that material, but it’s useful and can be vital once you start learning more.First, t-test, ANOVA and (OLS) regression are all the same model. You can use (some form of) regression for any problem that can be answered with a t-test or ANOVA. (Independent sample) t-tests can only handle the case where there is a single independent variable and it has precisely two levels. ANOVA handles the special case where all the independent variables are categorical, they can have any number of levels. Paired t tests can be dealt with in regression by making the dependent variable the difference in scores (this is what the paired t-test does). Repeated measures ANOVA shouldn’t really be used, it makes assumptions that are almost always unrealistic - better to use a multi-level model (which is a generalization of regression).What these methods have in common is that they have a single dependent variable and any number of independent variables and that the dependent variable is continuous. There are other regression methods for other kinds of dependent variables.Correlation and chi-square do not separate variables into dependent and independent. There are various kinds of correlation, but the most common is for two continuous variables. Chi-square is for categorical variables, most often for testing the association between two variables, but there are methods for one variable or more than two.
How do I get over feeling scared while studying?
I have seen this dynamic many times and highly suspect you are suffering from Obsessive Compulsive Disorder. It seems as if you are mostly struggling with a thought disturbance which doesn't have a ritualistic compulsive behavior component. It is very common for those struggling with some aspects of this condition to become so preoccupied with some type of feared outcome that they spend lots of time worrying over the seemingly potential risk. Here is a strategy on how to deal with this kind of anxious thinking. Whenever the thoughts begin to occur, remind yourself that this is an anxiety disorder and not a real legitimate concern. Immediately stop entertaining the thought. This is a very hard step to complete since most obsessions feels important and frightening. These thoughts seem like an imperative. To combat this anxiety disorder, it is necessary for you to resist this by reminding yourself repeatedly that the fear is not real but rather a symptom of a mental disorder. Take 10 slow diaphragmatic breaths. Here's a YouTube video demonstrating this type of breath work. Slowly inhale for 3 seconds and then exhale taking another 3 seconds. This type of breathing exercise will help to calm your overly excited nervous system. Replace the fearful thought with a new competing thought that distracts you. This new thought requires attention and concentration. In your case, you might want to find a style of studying that functions like this for you. Maybe hand write out the key points to the class material. Or walk around the room while memorizing the key points. If this doesn't work, try counting backwards from 1000 by 3's. This simple exercise is another helpful tool in gaining some measure of control over your thinking. For future projects, papers, or exams, develop a work or study schedule far in advance which breaks the work load into small manageable steps. Then strictly follow that plan each day regardless of your worry or fear. Whenever the obsessive fear starts to bother you, use the above steps repeatedly to address those anxious thoughts. If you follow these steps very carefully and completely, you will be able to break the stronghold that this obsessive-style of thinking has had on your life. It requires you to accept and to believe that these fearful thoughts are actually a type of an illness rather than a justified fear. Accepting this reality, however, will probably be the toughest part of this battle.