type_of_variables
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- | ====== Identifying variables ====== | ||
- | Please focus on dependent and independent variable first. You should be able to distinguish them. This is a good material to see if you understand the textbook alright. | ||
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- | ====== Dependent ====== | ||
- | A variable assumed to be dependent or be affected or caused by another (called the independent variable). If A is the result of the function of B, A is dependent variable. We can think A is a dependent variable because A is caused by the B('s function); A depends upon B('s function); A is affected by B('s function); A is effected by B('s function). | ||
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- | Example: | ||
- | A research story: A researcher wanted to know what happens when a car blocks another car on green light. He had a hunch -- frustration causes aggressive behavior. He conducted a field research. And here is what he did basically. | ||
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- | He took a spot (a light signal) where traffic is not so crowd in LA local area; He asked the driver (an experimenter) to stop on the light signal, to wait until another car approached behind his car, and not to move even when the light changed (to green). To make the research interesting, | ||
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- | The aggressive response (hone honking response) is the dependent variable, here. But, by using two types of cars, the researcher went further. He assumed that the degree of aggressive responses are affected by the status of the source of the frustration . That is, the researcher assumes that more aggressive responses will be observed when the frustrator' | ||
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- | ====== Independent ====== | ||
- | -- An independent variable is presumed to cause or determine a dependent variable. B is an independent variable, if B causes A, B affects A, B has an impact on A, B has effects on A. In the above case, the frustration causes aggressive responses. Therefore, frustration is the independent variable. | ||
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- | There is another opinion though! As mentioned, the researcher tweaked the situation by using two cars. He assumed that the status of the frustration sources will affect the aggressive responses -- if the status of the frustration source is high, less aggressive responses will occur, and vice versa. So, in this case, the independent variable is the status of frustrator. Why is that so (having two kinds of independent variables)? It has something to do with the control variable, which is explained below. | ||
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- | ====== Control ====== | ||
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- | -- A variable that is held constant in an attempt to clarify further the relationship between two other (dependent and independent) variables. Let's think of the above example. The researcher might have thought that there are differences in aggressive responses among the local drivers and out-of-state drivers. The latter might come from Logan, Utah, where people hardly use the horn in traffic. Or he might be a cab driver from New York enjoying a vacation in LA. Or she might come from London in which ... we don't know how they usually behave in such a situation. The researchers might think the responses of people outside of LA area are not valid since LA is not their everyday life environment and decide to exclude them. Now, we see the variable is controlled to see a specific relationship. | ||
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- | Another example. What if the researcher wants to choose only male subjects to see how they responded to the independent variable (Note that the researcher wanted to see only male)? In this case, the variable gender is a controlled (being held constant) variable. But, what if the researcher wanted to see the difference between male and female regardless the (high and low) status? In this case, the variable gender becomes a moderator (intervening) variable which will be explained the below. | ||
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- | ====== Moderator (intervening) ====== | ||
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- | -- A moderator variable is a variable that modifies the relationship between the independent and dependent variable. Let's think of the above example. We can draw a picture of how the variables work as below. | ||
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- | | The status | ||
- | | of the | ------------------> | ||
- | | frustrator | ||
- | |_____________| | ||
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- | </ | ||
- | Now, the researcher wanted to tweak the situation and see how male and female responded differently. The variable, gender, changes (moderates) the major relationship between the independent and dependent variable. So the picture is as follows. | ||
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- | < | ||
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- | | The status | ||
- | | of the | ------------------> | ||
- | | frustrator | ||
- | |_____________| | ||
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- | ______|______ | ||
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- | </ | ||
- | In fact, this is how the researcher' | ||
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- | But, some of you may think that the independent variable is " | ||
- | < | ||
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- | | Frustration | ------------------> | ||
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- | |_____________| | ||
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- | </ | ||
- | This is very simple and plausible. Suppose that this is a valid result of a study so that the researcher implicitly used this model in his study. What he did, then, is that he made another variable to see if it influences the dependent variable (Aggressive response). The variable is " | ||
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- | Please note that both control and moderator variables are considered as independent variables. It is up to the researchers to determine which are the independent, | ||
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- | | Frustration | | ||
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- | |_____________| | ||
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- | (control) | ||
- | | Status of | | ||
- | | frustrator | ||
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- | </ | ||
- | The same things can happen with gender variable. I told that gender is a moderating (intervening) variable in Figure 2. Then, what if the researcher wants to hold the independent variable constant (no status difference). Then he is controlling the status variable, use the gender variable as an independent variable. | ||
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- | You shouldn' | ||
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- | For tests... You should be aware of (1) that the independent variable does something to the dependent variable; (2) the independent variable does happens earlier than the dependent variable. So, in the statement (hypothesis) man are stronger than women, you should be able to figure out that the statement implicitly suggests: (1) that being a man may have caused more strength; (2) that gender (being a man) happened earlier than having more strength. | ||
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- | < | ||
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- | Sproull, N.. (1995). Handbook of research methods : a guide for practitioners and students in the social sciences, (2nd ed). Metuchen, NJ: Scarecrow Press. | ||
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- | Questions, Comments? -- please leave them in the class forum. | ||
- | Modified: | ||
type_of_variables.1459893248.txt.gz · Last modified: 2016/04/06 06:24 by hkimscil