Methods for Research Scenarios
What are the appropriate statistical methods for the given research scenarios?
Match the scenarios below to the correct listed method.
Scenario 1: Sheldon wants to know whether time of day and/or weather affect mood. To test this, Sheldon studies 10 participants in the morning on a hot day, 10 different participants in the evening on a hot day, 10 different participants in the morning on a rainy day and 10 different participants in the evening on a rainy day. Sheldon compares the mood ratings for these participants and determines whether time of day and/or weather significantly affect mood.
Scenario 2: Joey wants to know whether using a soundproof room improves performance on an auditory perceptual task. So, he recruits a sample of 50 participants and has them perform the auditory perceptual task twice – once in a regular room and once in a soundproof room. Joey then compares the scores to determine whether using a soundproof room significantly improves performance on an auditory perceptual task.
Scenario 3: Katie wants to know whether a long commute affects concentration at work. To test this, Katie recruits 60 participants for her study. These 60 participants are recruited because they self-report as having a long commute. Katie asks these participants to indicate their typical concentration level at work, on a scale from 1-5, where the average level in the general population is known to be 2.5, with standard deviation 1.5. Katie then determines whether having a long commute significantly affects concentration at work.
Scenario 4: Ashley wants to know whether tutoring significantly reduces mistakes on a statistics exam. To that end, Ashley recruits 40 students and divides them into two separate groups – those who do attend tutoring and those who do not attend tutoring. After these students complete a subsequent statistics exam, Ashley counts the number of mistakes each person makes. She then performs an analysis to determine whether people that attend tutoring make significantly fewer mistakes, on average, than people who do not attend tutoring.
Answers:
Scenario 1: non-directional independent-measures t-test (Chapter 10)
Scenario 2: non-directional repeated-measures t-test (Chapter 11)
Scenario 3: directional z-score hypothesis test (Chapter 8)
Scenario 4: non-directional independent-measures t-test (Chapter 10)
Scenario 1: This scenario involves examining the effects of two independent variables (time of day and weather) on a dependent variable (mood). Since there are multiple conditions and the same participants are not used in each condition, a one-way independent-measures ANOVA (Chapter 12) is suitable. It will determine if there are significant differences in mood based on different combinations of time of day and weather conditions.
Scenario 2: Here, Joey is comparing performance scores of the same participants in two different conditions (regular room and soundproof room), which are related measures. A non-directional repeated-measures t-test (Chapter 11) is appropriate to assess if there's a significant improvement in auditory perceptual task performance with the use of a soundproof room.
Scenario 3: Katie is examining the impact of a single independent variable (long commute) on a continuous dependent variable (concentration level). Since she compares a single group's scores to a known population mean, a directional z-score hypothesis test (Chapter 8) can determine whether having a long commute significantly affects concentration at work.
Scenario 4: Ashley is comparing two independent groups (tutoring vs. no tutoring) to see if there's a difference in the number of mistakes on a statistics exam. A non-directional independent-measures t-test (Chapter 10) is suitable for this scenario, as it assesses if the means of two independent groups are significantly different from each other.
The appropriate methods are selected based on the research design and variables being studied, including ANOVA, repeated-measures t-tests, z-score hypothesis tests, and independent-measures t-tests, as applicable.