Categorical Dichotomous Variables With Two Levels

Describe what you understand by ‘independent variable’ and ‘dependent variable’ in a scientific study? ( 5 points) An independent variable is something you have control over, what you can choose and manipulate. It is a variable that stands alone and doesn’t change by other variables. Although in some cases, you may not be able to manipulate the independent variable. It could be already there and or fixed. A dependent variable is the variable that’s being tested in an experiment. If the experimenter changes the independent variable, the change in the dependent variable is observed and recorded. For example a scientist is testing the effect of light and dark on the behavior of moths by turning a light on and off. The independent variable is the amount of light and the moth’s reaction is dependent variable. A change in the independent variable (amount of light) directly causes a change in the dependent variable (moth

Answer: This is a ordinal variable since education level is ordered from less to higher education and is put into 4 categories.

Dependent variables are ones that change due to the independent variable. Independent variables are variables that can be manipulated or measured. This influences the dependent variables.

A nominal variable is qualitative, or word orientated, distinct, mutually exclusive, completely exhaustive, and cannot be ordered (Walker, 2009).  Meaning, the variable is a descriptive word, i.e. color, can be distinguished from each other, its value coincides with only the category in which it was designed, has a designated category for each characteristic, and has no specific order (Walker, 2009).  A qualitative variable is strictly descriptive.  Whereas, a quantitative variable is numeric.  Therefore, the color of law enforcement officers’ uniforms is considered a nominal variable.

Independent variableIdentify the independent variable (IV), which is the variable that you hypothesize will cause or influence the other variable. *

First, state whether blood pressure in Table 2A would be a continuous variable or a discrete variable. Explain. Then supposing that the number of women in each of groups (non-users and users) were identified, would the number of women in each category be a continuous variable or a discrete variable? Explain.

As mentioned previously, this experiment would focus on three independent variables, which are income, race and education. The dependent variables were Democrats and Republicans, now it is time to break each variable into specifics. The first independent variable was income. Income was originally coded into five categories. The

3) A variable is a value that is usually a coefficient of a parameter in an equation. TRUE

Table 1 shows the amount of oxygen consumed by both types of peas in both the room temperature water and the ice water. The variables at the top of the data table are qualitative data because they are categorical data and are words, not numbers. However, the variables on the side of the graph are quantitative because they are all numbers. Graph 1 shows how the amount of oxygen consumed changed over time for each type of pea or beads in the room temperature water. Graph 2 showed the same thing as graph 1 except in the ice water. Both of these graphs have quantitative data on both the y and x-axis since the variables are all numbers. As you can see the difference in the amount of oxygen consumed varied based on the temperature of the water and whether it was sprouted or unsprouted.

damage to hair. The independent variable would be the different color hair dyes. The dependent

An example of Imbalance/Selectivity Bias: Practically the same as stereotyping – getting only opinions of a certain group or sex ; “ Which is the better sex male or female” but only asking that to females

Trap B) – don't fall into the trap of saying that a variable is how X influences Y (e.g. how smoking influences depression). That would involve a relationship bebween two variables, “smoking” and “depression.”

|Neither i nor ii | C 10. Variables are termed independent when they satisfy which of the following? |a. |The function value depends upon their values. | |b.

For each of the four items listed. Indicate whether the variable is categorical or numerical. If it is numerical. Is it discrete or continuous?

Often times as researchers, we will take continuous variables and break it up into categories, typically for the purpose of grouping, or to measure an outcome measure. We usually decide on a reasonable cut-point and place the data in the appropriate category. Streiner (2002) asserts that this categorization results in lost information, reduced power of statistical tests, as well as an increased probability of a Type II error. In Streiner (2002) article, written primarily for researchers, he states that the only justified reasons for dichotomizing a continuous variable is when the distribution is highly skewed or the data shows a non-linear relationship with another variable.