Independent and Dependent Variables An independent variable ( also called the manipulated variable) can stand alone and it is the variable. You are the one that changes it, not the other variable. The Dependent variable is the outcome of the Independent variable. If you wanted to see if more sleep improves your score on your test, the dependent variable is how well you preformed on the test.
One of the steps of the scientific method is testing your hypothesis or the experiment. You test your observation which could be anything. Which brand of pencil is the strongest? It could be anything. First you must decide the independent variable. The variable you will be changing on purpose. Then the Dependent variable is the outcome of the Independent variable. The control variables are the things you must keep the same or else no one can get the same results.
To have a proper experiment, you must have control variables. You have to keep some things the same in experiments, like age, height, weight, etc. If they were not the same, you could not repeat the experiment, because you will get different results.
Qualitative and quantitative are both types of observations. Qualitative data is something you measure with your five senses. Quantitative data is something you measure and is numerical. Both have advantages and disadvantages. Quantitative data can give us a scientific view of the relationship between two variables. On the other hand, it doesn't tell us why that relationship exists. Qualitative data can tell us emotions and how people react. But it doesn't allow us to test the theory scientifically.
If you see a ton of people walk to one house, you will assume that they are throwing a party. That is an inference. an Inference is a guess you form with observations. It is formed from facts, evidence, or clues. Those clues lead you to guess about what you think is true. If you are a scientist, you make observations to make inferences. Those inferences can be tested, and that's called a hypothesis.
An observation is something you notice with your five senses. It's a remark, statement, or comment on something you have seen, smelled, taste, heard, or touched. An observation is an action to gain information.