# on which variable will the difference be measured to determine if the other variable had a statistically significant affect on it?

PY3350 Research Methods

James C. Guy, Ph.D.

Scales and Variables Assignment

INSTRUCTIONS: After reading the helps below, identify the scale of measurement and/or the IV and DV for each of the questions on page two. Use this paper to record your answer and upload it into Bb.

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Variables can be Nominal, Ordinal, Interval, or Ratio.

Designs also have an Independent Variable (IV) and a Dependent Variable (DV), or multiples of these as you will learn in a later module on factorials designs.

There are some hints to remembering the definition and being able to identify these. Consider the following, or you may come up with some on your own.

SCALES

NOMINAL= “name”

(Begins with “n” and just names something)

ORDINAL= “order”

(Begins with “o” and puts data in order without a specific distance between the points)

INTERVAL=”even”

(Goes one step beyond the Ordinal in that the distances between the data points are even; It does not have a “true zero” point meaning zero does not mean the absence of something.)

RATIO=”zero”

(ratiO/zerO; The distances between data points are even as in the Interval scale but there is also a true zero meaning that “zero” on the scale actually means that absence of the thing being measured.)

VARIABLES

Independent Variable (IV) = What “I” do to this variable affects the DV (The IV is the one that is manipulated)

Dependant Variable (DV) = This variable “depends” on what I do to the IV (The DV is the one that changes as a result of the IV -assuming there is an affect of one on the other)

QUESTIONS

1. A researcher is measuring gender and identifies Females with a “1” and Males with a “2”. Which scale is being used in this case?

2. A researcher is measuring what place runners place in a race compared to how much caffeine they consume before the race. The amount of caffeine is measured in grams and the runners are measured based on the order they cross the finish line. Which scale would be used for the runners and which one for the caffeine?

3. A scientist is measuring the affect of adding alcohol to water by measuring the temperature of water with and without alcohol added after being put in a freezer for 24 hours. The temperature is being measured in Celsius with “0” being considered the freezing point of water. Would the temperature be measured as an Interval scale or a Ratio scale? Clearly explain the reason for your answer.

4. A researcher is comparing family income to personality of the father. Personality is measured using the Myers-Briggs (MBTI) categories, and income is measured using a self-report of income. Which scales would be used for each of these varaibles?

5. Give a brief summary of a research you might conduct such as those in the questions above. Then identify which would be your DV and which would be your IV. State why.

6. A researcher is giving rats alcohol in the lab and testing how fast they complete the Murry Water Maze task. What is being manipulated in this study (e.g. Which is the IV?) and why is it considered “manipulated”?