PSYC 510
Introductory Concepts: Practice Worksheet – Identifying Variables
Review of Material: Independent vs. dependent variables, confound vs. extraneous variable (Module 1)
Information from: Module 1 presentation “Introduction to Research Methods” and Ch. 1 Jackson – section “Explanatory Method”
Additional practice: Jackson ch. 1 Chapter exercises # 7A-D; MC self-test Q9-12 (answers in e-book for self-check)
Note: this is an OPTIONAL worksheet to practice applying some of this module’s key concepts. Please make sure you complete all assigned readings and watch this module’s videos before attempting the worksheet! Try to complete it on your own, then check your answers with the answer key details (at the end of the document).
Practice 1
Scenario: Educational psychologists use teacher ratings of classroom shyness (on a nine-point Likert scale, where 1 = not at all shy in class and 9 = very shy in class) to measure children’s temperament. They wanted to see if this differs between boys and girls in a third grade classroom during the math period.
Questions: Identify the independent variable, dependent variable, and one constant. Try to identify a confounding variable as well, including your justification for why it may be a confound.
Practice 2
Scenario: Researchers place unobtrusive video recording devices in the hallway of a local high school. Later, coders view tapes and code how many students are using cell phones in the 4 minute period between classes.
Questions: Identify the independent variable, dependent variable, and one constant. Try to identify a confounding variable as well, including your justification for why it may be a confound.
Practice 3
Scenario: A human resource manager distributes a survey to employees who have been hired in the last 3 years to see if stress levels are similar between salaried and hourly employees. The survey used a sliding scale (akin to Likert) ranging from 1 – 10 for each of the 10 questions. This number was averaged so that a single value ranging from 1 – 10 (strongly disagree to strongly agree) represented each person.
Questions: Identify the independent variable, dependent variable, and one constant. Try to identify a confounding variable as well, including your justification for why it may be a confound.
ANSWER KEY for Identifying Variables (Module 1)
Practice 1
Scenario: Educational psychologists use teacher ratings of classroom shyness (on a nine-point Likert scale, where 1 = not at all shy in class and 9 = very shy in class) to measure children’s temperament. They wanted to see if this differs between boys and girls in a third grade classroom during the math period.
Questions: Identify the independent variable, dependent variable, scale of measurement for each, and one constant. Try to identify a confounding variable as well, including your justification for why it may be a confound.
Answer:
· Independent variable (IV) is what is the “cause”. In a “true” experiment, it is manipulated. However, in this scenario, the researcher believes gender may affect temperament. Thus, the IV is gender, and is a “subject variable” (it is still an IV – but to reflect our knowledge it isn’t manipulated, we can further clarify it is a subject variable).
· The Dependent Variable (DV) is what is “the effect”, so in this scenario, it is “temperament” (as measured by classroom shyness).
· Remember, a variable is something that has more than one value in the study (hence, gender and shyness are both variables). In this particular scenario, a constant (something that does NOT vary), would be third grade classroom during math period.
· A confounding variable is a variable that was not controlled in the study and after the fact, became apparent that it may indeed influence the results of the study. So, we get to use our imaginations here. There are many different acceptable answers, depending on your justification. Here’s two examples:
· Student perception of the teacher may influence classroom shyness (maybe not related to the math class at all, but rather, who is teaching the math class).
· Personal issues that happen to occur around the time of the study may influence results. For instance, if a plant shuts down and half of the parents have lost their jobs that year, some of the students’ behaviors may be affected. Or, if a stomach virus is going around and several of the students simply don’t feel good at the time of the study, their typical behaviors may be affected.
Practice 2
Scenario: Researchers place unobtrusive video recording devices in the hallway of a local high school. Later, coders view tapes and code how many students are using cell phones in the 4 minute period between classes.
Questions: Identify the independent variable, dependent variable, scale of measurement for each, and one constant. Try to identify a confounding variable as well, including your justification for why it may be a confound.
Answer:
· Independent variable (IV): So this is a “trick” scenario in that it is a descriptive study. The goal is to describe how many students are using cell phones. Thus there is no Independent Variable. Nothing is manipulated or believed to be the cause.
· DV: The dependent variable is what the researcher measures. In this scenario, that is the number of students using cell phones.
· A constant in this scenario is the location of the video recording devices, or the high school, or even the 4 minute period between classes. (Anything held “constant” for the study).
· Again there are plenty of options for confounding variables, as there wasn’t any “control” in the study. For instance:
· If the study was conducted the day prom tickets went on sale, more students may be on their phones than normal, thus skewing the interpretation of their data.
· If the hallway selected is only where “gifted” or “advanced” classes are held, then conclusions may not generalize to all students, just those typically in that particular area. (Same instance if it is in a hallway by the locker rooms for football, or the music hall, et cet.)
Practice 3
Scenario: A human resource manager distributes a survey to employees who have been hired in the last 3 years to see if stress levels are similar between salaried and hourly employees. The survey used a sliding scale (akin to Likert) ranging from 1 – 10 for each of the 10 questions. This number was averaged so that a single value ranging from 1 – 10 (strongly disagree to strongly agree) represented each person.
Questions: Identify the independent variable, dependent variable, scale of measurement for each, and one constant. Try to identify a confounding variable as well, including your justification for why it may be a confound.
Answer:
· Independent variable (IV): What is the “cause”? the type of employee (again this is actually a subject variable). So, the IV is Type of Employee.
· DV: What is the “effect”, or what is the researcher actually collecting data on? Stress levels. So, the DV is stress levels.
· A constant is the sample being restricted to employees who have been hired in the last 3 years. Since there is no variation in this, it is a “constant”.
· Potential confounding variables (there are more as long as you justify your rationale!)
· Gender. Perhaps more males are salaried than hourly, and in general females are reported to have more stress, so since the two comparison groups may not have similar ratios of males / females, this may be a confound.
NOTE: There are still opportunities for extra practice! Try completing Jackson ch. 1 Chapter exercises # 7A-D and the multiple choice (MC) self-test Q9-12 from chapter 1 (answers in e-book for self-check)
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