MOD 5: Quantitative Research Questions and Designs

The most appropriate research design is determined by the 

type of research question

A researcher is interested in knowing what percentage of American college students have experienced traveling outside of the country. Which of these research designs would be most appropriate for answering this research question?

Descriptive

Which of these types of variables is(are) not measured in correlational research?

Control variable

Through a short survey, a researcher measures the number of extracurricular activities and the GPA for a group of high school students. The results indicate that students with a higher number of extracurricular activities tend to have higher GPAs. Based on this study design, what type of claim can be made?

There is a relationship between extracurricular activities and GPA

When conducting experimental research, which variable is manipulated?

Independent variable

Why is random assignment important in experimental research?

It ensures two groups are equivalant

What is the purpose of the control condition in experimental research?

It serves as a comparison to the experimental condition

How are quasi-experimental designs different from correlational designs? 

Quasi-experimental designs may attempt to manipulate the independent variable

A researcher compares the emotional intelligence scores of students attending a large, urban school with the scores of students attending a small, rural school. The groups were matched for variables such as gender and socioeconomic status. The data indicate that the students in the small, rural school have statistically higher levels of emotional intelligence than the students in the large, urban school. Can it be concluded that attending a small, rural versus a large, urban school causes differences in emotional intelligence?

No, this was a quasi-experimental research design and there may be alternative explanations for the difference in scores.

Which of these is always a part of quasi-experimental designs?

Measurement of the dependent variable

Which of these claims can be made from a study using a quasi-experimental design? 

A claim about associative relationship between variables

Dr. Zhu wonders if anxiety is related to weight change. She recruits participants and measures their weight in September and then again 1 year later. She also counts the number of life stressors (e.g., moving, losses) that each has experienced over this year. From these data, Dr. Zhu calculates the change in weight from the beginning to the end of the study. What type of claim can be made from the design of this study?

A claim about the associative relationship between variables

Dr. Prenovost wants to determine whether team cohesion is related to success on the playing field. She works with 20 high school soccer teams in her region. Ten of the teams are randomly assigned to attend a 3-hour workshop on building team cohesion. The other 10 teams attend a 3-hour skills-based session. She then counts wins and losses over the regular soccer season. What type of claim can be made from the design of this study?

A claim about the causal relationship between variables

Dr. Nissen also wants to determine whether team cohesion is related to success on the playing field. He observes high school soccer teams during practice and counts the number of times team members congratulate each other during play. He splits the teams into two groups: teams that show high cohesion and teams that show low cohesion. The final groups are matched in terms of geographic location and median income for families within the school district boundaries. Dr. Nissen then counts wins and losses over the regular soccer season for each group. What type of claim can be made from the design of this study?

A claim about the associative relationship between variables

Dr. Abukhazneh wonders if fidgeting is related to anxiety. He randomly divides his participants into two groups and gives one group a test that has no correct answers, which makes the test seem extremely difficult and provokes high anxiety. The other group is given a test with obvious answers, which makes the test seem very easy and does not provoke anxiety. While the participants are taking the test, Dr. Abukhazneh counts how long they each spend engaged in fidgeting behavior such as tapping their feet and hands or playing with their hair.  What type of claim can be made from the design of this study?

A claim about the causal relationship between variables

To assess mental health in college students, 60 participants completed questionnaires to measure symptoms of anxiety and depression. A positive relationship was found, such that as anxiety symptoms increased, depression symptoms increased as well. Which of Mill’s criteria have been met in this study?

Covariance

Dr. Hopkins is interested in whether there is a relationship between watching the morning news and irritability throughout the day. She conducts a month-long study, in which at the end of every day, her study participants complete a survey, reporting on both their news consumption and their mood. She finds a positive relationship, such that as time spent watching the morning news increases, irritability increases as well.  Which of Mill’s criteria was not met in this study?

Elimination of alternative variables

In order to eliminate alternative explanations, you should

Conduct an experiment under highly controlled conditions

If we design a study in which only the independent variable differs between the experimental and control conditions, then we have achieved which of Mill’s criteria?

Eliminate alternative variables

If we design a study where the measure of the independent variable is related to the measure of the dependent variable, then we have achieved which of Mill’s criteria?

Covarience

A researcher used a convenience sample of 30 undergraduate students from a small liberal arts college to examine the relationship between sleep and memory. Because this is not a random sample of the population of adults in the United States, these results may not generalize to all adults in the United States. This study has low [BLANK] validity. 

external

Dr. Morley wanted to know whether using an electronic sleep-promoting device before going to bed has an influence on the amount of time necessary to fall asleep compared to reading a book before bed. Fifty participants were randomly assigned to either the electronic device group or the book group; time to fall asleep was measured for both groups. Because only the independent variable was manipulated and there was random assignment to groups, any difference in time to fall asleep should be due to the activity prior to falling asleep. This study has high [BLANK] validity. 

Internal

A researcher wanted to examine the relationship between the number of assignments due per week and anxiety levels in college students. The number of assignments due was assessed through viewing various course syllabi due dates. The measurement for anxiety was a standardized anxiety test that was known to be an accurate measure of anxiety. This study would have high [BLANK] validity.

Construct

Imagine that a new test is designed to measure emotional intelligence. The test provides consistent results when participants take it multiple times over a 6-month period. However, experts have questioned whether all the aspects of emotional intelligence are included in the test. This test has [BLANK].

high reliability, low validity

 If you ask the question “Does the methodology of this study allow you to answer your causal research question?” then you are concerned with which type of validity?

Internal

Which types of validity are essential to all types of study claims? 

Construct and statistical

A research lab reported that there was a significant correlation between distributed practice and exam score. The researchers for this study would not need to be concerned with which type of validity, because it would not be possible to attain in this example?

Internal

As guidance for incoming students, a resident assistant (RA) for the campus dormitory advised students to study in the library rather than their dorm rooms. In support, the RA determined that there was a significant difference in the number of words recalled in a memorization test after studying in the campus library compared to one of the dorm rooms. For their campus, the RA should be the least concerned with which type of validity?

External

Why is construct validity important to all research claims?

It is important for every study to have accurate manipulations and measurements for the variables of interest.

In an effort to understand the causal link between violent crime and the cost of illegal guns in large U.S. cities, a researcher documented that instances of violent crime are higher in cities with a larger supply of illegal guns. Which of the following forms of validity is a concern for this study? 

Internal