Week 2: Basic Design (True Experiment) Flashcards
What is a true experiment?
A: In a true experiment we manipulate one variable and measure its effect on the other variable. The variable that is manipulated is called the independent variable, and the variable that is measured is called the dependent variable. We manipulate the independent variable to assess its effect on the dependent variable and everything else must be controlled.
B: A true experiment involves manipulating both variables simultaneously and observing the combined effects on each other without distinguishing between an independent or dependent variable.
C: In a true experiment, variables are left uncontrolled, allowing for natural fluctuations to influence the relationship between the manipulated and measured variables.
A: In a true experiment we manipulate one variable and measure its effect on the other variable. The variable that is manipulated is called the independent variable, and the variable that is measured is called the dependent variable. We manipulate the independent variable to assess its effect on the dependent variable and everything else must be controlled.
- Independent Variable (IV):
> Manipulated variable - Dependent Variable (DV):
> Measured variable
EXAMPLE:
> Hypothesis: “Watching violent television CAUSES aggressive behavior.”
> Independent variable = violent TV (this is what we manipulated, so maybe one group watches 0 hours of violent TV and the other watches 10 hours per week and then you’ll compare these two groups)
> Dependent variable = aggression (this is what we’re measuring)
What are the characteristics of an independent variable?
A: An independent variable is a constant factor that remains unchanged throughout an experiment, providing a stable background against which the dependent variable can be measured.
B: The independent variable is solely determined by the participants themselves, without any manipulation by the researcher, allowing for natural variations in the variable without control or random assignment.
C: The independent variable is manipulated by the researcher, meaning they create conditions and assign participants to experience different levels of the variable. It must have a minimum of two levels or conditions. Participants must be randomly assigned to the levels of the independent variable. The independent variable must be operationally defined in detail.
C: The independent variable is manipulated by the researcher, meaning they create conditions and assign participants to experience different levels of the variable. It must have a minimum of two levels or conditions. Participants must be randomly assigned to the levels of the independent variable. The independent variable must be operationally defined in detail.
What does the term manipulation mean?
A: Manipulation refers to participants having complete control over the experimental conditions, deciding on the levels they want to experience without any intervention from the researcher.
B: The researcher is going to create conditions that participants will be assigned to experience and two levels are the absolute minimum (0 minutes of violent TV vs. 10 minutes of violent TV).
C: The term manipulation is misunderstood as referring to the fabrication of data, allowing researchers to manipulate or alter the results to fit their expectations without regard for the actual conditions experienced by participants.
B: The researcher is going to create conditions that participants will be assigned to experience and two levels are the absolute minimum (0 minutes of violent TV vs. 10 minutes of violent TV).
What does the term random assignment mean?
A: Random assignment involves letting participants choose the experimental conditions they want to experience, ensuring that their personal preferences determine the levels of independent variables.
B: Participants are deliberately placed in conditions based on certain characteristics or traits that the researcher believes are relevant to the study.
C: Participants must be randomly assigned to the levels of our independent variables. This is a fundamental tenet of experimental design. There should be nothing about the participants themselves that determines what condition they will experience. So our participants will be randomly assigned to the conditions or levels of our independent variables (0 minutes of violent TV vs. 10 minutes of violent TV).
C: Participants must be randomly assigned to the levels of our independent variables. This is a fundamental tenet of experimental design. There should be nothing about the participants themselves that determines what condition they will experience. So our participants will be randomly assigned to the conditions or levels of our independent variables (0 minutes of violent TV vs. 10 minutes of violent TV).
What is a construct?
A: A construct is a specific and precisely defined variable that leaves no room for interpretation or variation. It represents a concrete and universally agreed-upon concept in research.
B: A general concept or idea that is broad and not concretely defined. Constructs can mean different things to different people. Examples: intelligence, motivation, anxiety, and safety.
C: A construct is thought to be a highly specific and narrowly defined idea that is universally agreed upon, lacking the inherent subjectivity and variability associated with broad concepts like intelligence or motivation.
B: A general concept or idea that is broad and not concretely defined. Constructs can mean different things to different people. Examples: intelligence, motivation, anxiety, and safety.
EXAMPLE:
Independent variable = Violent TV
Dependent variable = Aggression
What is an operational definition?
A: An operational definition is a vague and imprecise description of a variable, allowing for subjective interpretation and lacking the need for concrete measurement or manipulation.
B: An operational definition takes a construct and gives much more detail about how that variable will be studied and measured. An operational definition provides a concrete, quantitative, or qualitative way to manipulate an independent variable or measure a dependent variable. It allows others to replicate a study based on the precise description of how variables are defined and measured.
C: The operational definition is perceived as a rigid and inflexible set of rules dictating how a variable should be studied and measured, leaving no room for adaptability or variations in research approaches.
B: An operational definition takes a construct and gives much more detail about how that variable will be studied and measured. An operational definition provides a concrete, quantitative, or qualitative way to manipulate an independent variable or measure a dependent variable. It allows others to replicate a study based on the precise description of how variables are defined and measured.
EXAMPLE:
Independent variable:
> Quantitative (# of hours of violent TV watched per week, 0 vs. 10 for example)
> Qualitative (type of violent TV watched, cartoons, news, movie for example - everyone would watch the same amount but the type of violence they are watching will be different).
Dependent variable:
> # of times a child hits another child on the playground
> # of children in their class that describe them as mean
> > Ask teachers to rate their behavior on a certain scale
> People assess their own thoughts, feelings, beliefs,
habits, skills, etc.
> Observe participants and measure their behavior
> Biological measurements (heart rate, blood pressure, cortisol levels)
What is a quantitative manipulation?
A: A quantitative manipulation looks at how much of something a participant will receive or experience. In the example of violent TV exposure, it would involve assigning different groups to watch different amounts of violent TV, like zero hours per week versus 10 hours per week. A quantitative manipulation measures different amounts or levels of the independent variable.
B: A quantitative manipulation involves manipulating variables based solely on qualitative differences, disregarding any consideration for the quantity or amount of the variable experienced by participants.
C: A quantitative manipulation is thought to involve manipulating variables in a way that doesn’t measure different amounts or levels, neglecting the essential aspect of quantifying the independent variable.
A: A quantitative manipulation looks at how much of something a participant will receive or experience. In the example of violent TV exposure, it would involve assigning different groups to watch different amounts of violent TV, like zero hours per week versus 10 hours per week. A quantitative manipulation measures different amounts or levels of the independent variable.
What type of graph would be appropriate for a quantitative manipulation?
A: Line graph
B: Bar graph
C: Histogram
A: Line graph
> A line graph is appropriate for data from a quantitative manipulation because the midpoints along the x-axis are meaningful. When groups experience different amounts of the independent variable, like 0 hours and 10 hours of violent TV, there is a meaningful connection between those points on a continuum. A line can be drawn connecting the data points, and predictions can be made for intermediate values like 5 hours.
> There is a meaningful halfway point between 0 hours and 10 hours - it’s 5 hours
> Only quantitative manipulations can show functional relationships, not qualitative manipulation
> The independent variable will always be on the x-axis (horizontal)
> The dependent variable will always be on the y-axis (vertical)
What is a qualitative manipulation?
A: Manipulating variables solely based on the amount or quantity, ignoring any distinctions in the types or categories of the variable experienced by participants.
B: A qualitative manipulation is perceived as a method that doesn’t involve comparing different categories or kinds of the independent variable, overlooking the critical aspect of qualitative differences.
C: A qualitative manipulation differentiates groups based on the type of thing they experience, rather than the amount. In the example of violent TV, it could involve comparing watching violent cartoons versus TV crime shows. A qualitative manipulation compares different categories or kinds of the independent variable, rather than different amounts.
C: A qualitative manipulation differentiates groups based on the type of thing they experience, rather than the amount. In the example of violent TV, it could involve comparing watching violent cartoons versus TV crime shows. A qualitative manipulation compares different categories or kinds of the independent variable, rather than different amounts.
True or false: Only using two conditions is limiting?
A: True
B: False
A: True
> Only using two conditions for a quantitative manipulation is somewhat limiting, because it only provides two data points. With only two points, the relationship can only be a straight line - either increasing, decreasing, or staying the same. Using three or more conditions allows the researcher to check if there is a nonlinear or functional relationship between the variables, rather than just an assumption of a straight linear relationship. It provides more data points to reveal potential nuances in the relationship.
What is a nonlinear/functional relationship?
A: A nonlinear/functional relationship always represents a perfectly straight line, with no variation or curvature in the relationship between two variables.
B: A nonlinear or functional relationship refers to when the relationship between two variables is not a straight linear line. Using three or more levels of the independent variable allows the researcher to check if the data shows a nonlinear pattern, such as aggression increasing dramatically from 0 to 5 hours of TV exposure but leveling off from 5 to 10 hours, rather than steadily increasing the whole time. It reveals if the relationship has a more complex, nonlinear shape rather than simply going up or down in a straight line.
C: A nonlinear/functional relationship is thought to be limited to situations where the relationship is chaotic and unpredictable, disregarding the possibility of a structured and complex pattern.
B: A nonlinear or functional relationship refers to when the relationship between two variables is not a straight linear line. Using three or more levels of the independent variable allows the researcher to check if the data shows a nonlinear pattern, such as aggression increasing dramatically from 0 to 5 hours of TV exposure but leveling off from 5 to 10 hours, rather than steadily increasing the whole time. It reveals if the relationship has a more complex, nonlinear shape rather than simply going up or down in a straight line.
> These types of relationships are easier to see with 3 or more conditions. Actually, 3+ levels is the only way we can see a nonlinear/functional relationship.
> For example: 0 hours/week, 5 hours/week, and 10 hours/week
Why does the range (minutes vs. hours) we choose to study matter?
A: The range is irrelevant, assuming that any range, whether narrow or wide, would provide an equally comprehensive understanding of the relationship between variables.
B: The range we choose to study matters because if the range is too narrow, it may not reveal the true nature of the relationship between the variables. As an example, if the range studied was 0 minutes to 10 minutes of TV exposure, there may be no observable difference, but that narrow range doesn’t show the full picture of what could happen over a wider range like 0 to 10 hours. A narrow range provides a limited view like a close-up photo, while a wider range gives more insight into the overall relationship.
C: The range selected is thought to have no impact on the ability to observe differences between variables, negating the idea that a wider range could offer more comprehensive insights than a narrow one.
B: The range we choose to study matters because if the range is too narrow, it may not reveal the true nature of the relationship between the variables. As an example, if the range studied was 0 minutes to 10 minutes of TV exposure, there may be no observable difference, but that narrow range doesn’t show the full picture of what could happen over a wider range like 0 to 10 hours. A narrow range provides a limited view like a close-up photo, while a wider range gives more insight into the overall relationship.
So with quantitative manipulation, what are your two biggest concerns?
A: In quantitative manipulation, the number of levels or conditions of the independent variable is deemed irrelevant, and any number of levels, even just two, is considered sufficient for a thorough examination of the relationship between variables.
B: The range of data chosen in quantitative manipulation has no impact on the validity of the study, and a narrow range is thought to be just as effective in revealing the true nature of the relationship as a wider range.
C: The number of levels or conditions of the independent variable. At least three levels are needed to check for nonlinear relationships. And the range of data chosen. The range needs to be wide enough to potentially reveal the true nature of the relationship between variables, rather than a narrow range that may show no observable effects.
C: The number of levels or conditions of the independent variable. At least three levels are needed to check for nonlinear relationships. And the range of data chosen. The range needs to be wide enough to potentially reveal the true nature of the relationship between variables, rather than a narrow range that may show no observable effects.
What type of graph would be appropriate for a qualitative manipulation?
A: Line graph
B: Bar graph
C: Histogram
B: Bar graph
> A bar graph is appropriate for data from a qualitative manipulation because there is no meaningful connection or continuum between the categories. With a qualitative manipulation comparing different types rather than amounts, like violent cartoons vs. crime shows, there is no halfway point between the categories like there is with quantitative amounts. Since there is no continuum across discrete categories, a bar graph is more suitable than a line graph to display the data.
> There is no meaningful halfway point between cartoons and the news
What are the characteristics of a dependent variable?
A: It is the factor that is measured by the researcher to assess changes or effects. It needs to be operationally defined precisely to guide how it will be measured in the study. The scale of measurement used to collect data on the dependent variable needs to be identified as nominal, ordinal, interval, or ratio.
B: The dependent variable is thought to be a factor measured by participants themselves, without the need for operational definitions or precise guidance from the researcher.
C: The scale of measurement for the dependent variable is perceived as irrelevant to the study of the independent variable, disregarding the importance of identifying the measurement scale for accurate data collection.
A: It is the factor that is measured by the researcher to assess changes or effects. It needs to be operationally defined precisely to guide how it will be measured in the study. The scale of measurement used to collect data on the dependent variable needs to be identified as nominal, ordinal, interval, or ratio.