For each question, list the following:
1.
All independent and dependent variables (2 points)
2.
All null and alternate hypothesis/hypotheses (directional wherever possible) (2 points)
3.
All appropriate descriptive statistics that you think are needed for all variables and potential levels. (2 points)
4.
The appropriate inferential statistic to conduct (be specific, such as “independent t-test” rather than “t-test.”). Don’t forget to include effect size and post hoc tests. (4 points)
Keep in mind, some of the problems may require the same statistical test—don’t be afraid to repeat (maybe even several times) a test if you feel the description warrants it. Additionally, more than one inferential test might be applicable.
Analyses to choose from:
Single sample z-test, single sample t-test, independent t-test, dependent t-test, one-way independent ANOVA, one-way repeated measures ANOVA, two-way independent ANOVA, Correlation/regression, chi-square goodness-of-fit test, chi-square test for independence.
1. To examine the relationship between alcohol consumption and birth weight, a researcher selected a sample of
n
= 20 pregnant rats and mixed alcohol with their food for 2 weeks before the pups were born. One newborn pup was randomly selected from each subject's litter to produce a sample of
n
= 20 rat pups. The average birth weight, in grams for the
n
= 20 pups was calculated, and compared to the known average birth weight for rats not exposed to alcohol during gestation.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
2. To examine the relationship between texting and driving skill. a researcher set up a driving circuit using orange cones in the high school parking lot. A group of students was tested driving on the circuit, once while receiving and sending text messages and once without texting. For each student. the researcher recorded the number of orange cones struck while driving each circuit.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
3. There is some evidence indicating that people with visible tattoos are viewed more negatively than people without visible tattoos (Resenhoeft, Villa. & Wiseman, 2008). In a similar study, a researcher showed male college students photographs of an attractive woman. For one group of participants. the target was photographed with a large tattoo on her shoulder and for a second group her photograph showed no tattoo. The researcher compared the target’s ratings for the two groups to determine whether the tattoo had any effect on perceived attractiveness.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
4. A researcher investigated different combinations of temperature and humidity to examine how heat affects performance. The researcher compared three temperature conditions (70°, 80°, and 90°) with a high humidity and a low humidity condition for each temperature. A separate group of participants was tested in each of the six different conditions. For each participant. the researcher recorded the number of errors on a problem-solving task to learn how different combinations of temperature and humidity influence performance.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
5. Hallam. Price, and Katsarou (2002) investigated the influence of background noise on classroom performance for children aged 10 to 12 years. Students in one classroom worked on an arithmetic task with calming music in the background. Students in a second classroom heard aggressive. exciting music. and students in a third room heard no music at all. The researchers measured the number of problems answered correctly for each student to determine whether the music conditions had any effect on performance.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
6. A researcher investigated the relationship between personality and birth order position. A sample of college students was classified by birth-order (1st, 2nd, 3rd, etc) and given a personality test that measured the degree of extroversion on a 50-point scale.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
7. Standardized measures seem to indicate that the average level of anxiety has increased gradually over the past 50 years (Twenge, 2000). In the 1950s, the average score on the Child Manifest Anxiety Scale was 151. A researcher administers the same test to a sample of n = 50 of today’s children to determine whether there has been a significant change to the average anxiety level.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
8. Belsky, Weinraub, Owen, and Kelly (2001) reported on the effects of preschool care on the development of young children. One result suggests that children who spend more time away from their mothers are more likely to show behavioral problems in kindergarten. Suppose that a kindergarten teacher is asked to rank order the degree of disruptive behavior for the
n
= 20 children in the class. The researchers then interview each child’s parents to determine how much time the child spent in preschool. The researchers plan to use the data to determine whether there is a relationship between preschool experience and disruptive behavior.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
9. McGee and Shevlin (2009) found that an individual’s sense of humor had a significant effect on how attractive an individual was perceived to be by others. Female college students were given brief descriptions of four potential romantic partners, all described in equivalent terms as being single, ambitious, and with good job prospects. Two of the men were also described as having a great sense of humor, while the other two men were not described that way. After reading the four descriptions, the participants were asked to state which of the four she found the most attractive. The number of times the two categories of men (humor vs. no humor) was chosen was recorded.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
10. Numerous studies have found that males report higher self-esteem than females, especially for adolescents (Kling, Hyde, Showers, & Buswell, 1999). A recent study found that males scored an average of 8 points higher than females on a standardized questionnaire measuring self-esteem. The researcher would like to know whether this is a significant difference.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
11. Research has demonstrated that IQ scores have been increasing, generation by generation, for years (Flynn, 1999). A researcher would like to determine whether this trend can be described by a linear equation showing the relationship between age and IQ scores. The same IQ test is given to a sample of 100 adults who range in age from 20 to 85 years. The age and IQ score are recorded for each person.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
12. A researcher investigated the effectiveness of acupuncture treatment for chronic back pain. A sample of
n
= 20 participants was obtained from a pain clinic. Individuals rated their current level of pain and then began a 6-week program of acupuncture treatment. At the end of the program, the pain level was rated again and the researcher recorded whether the pain has increased or decreased for each participant.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
13. Research results indicate that physically attractive people are also perceived as being more intelligent (Eagly, Ashmore, Makhijani, & Longo, 1991). As a demonstration of this phenomenon, a researcher obtained a set of
n
= 25 photographs of male college students. The photographs were shown to a sample of female college students who used a 7-point scale to rate several characteristics, including intelligence and attractiveness, for the person in each photo. The average attractiveness rating and the average intelligence rating were computed for each photograph. The researcher plans to use the averages to determine whether there is relationship between perceived attractiveness and perceived intelligence.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
14. Research has shown that people are more likely to show dishonest and self-interested behaviors in darkness than in a well-lit environment (Zhong, Bohns, & Gino, 2010). Students were given a quiz and then asked to grade their own papers while the teacher read the correct answers. A group of students was tested in a well-lit room, a moderately lit room, and a dimly-lit room. The researchers recorded the number of correct answers reported by each student to determine whether there was a significant difference between the three groups.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
15. There is some evidence suggesting that you are likely to improve your test score if you rethink and change answers on a multiple-choice exam (Johnston, 1975). To examine this phenomenon, a teacher encouraged students to reconsider their answers before turning in exams. Students were asked to record their original answers and the changes that they made. When the exams were collected, the teacher found that 18 students improved their grades by changing answers and only 7 students had lower grades with the changes. The teacher would like to know if this is a statistically significant result.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
16. A researcher is evaluating customer satisfaction with the service and coverage of three phone carriers. Each individual in a sample of n = 25 uses one carrier for 2 weeks, then switches to another for 2 weeks, and finally switches to the third for 2 weeks. Each participant then indicates which of the three they prefer.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
17. There is some research indicating that college students who use Facebook while studying tend to have lower grades than non-users (Kirschner & Karpinski, 2010). Students were surveyed to determine the amount of Facebook use during the time they were studying or doing homework. Based on the amount of time spent on Facebook. students were classified into three groups (high. medium. and low time) and their grade point averages were recorded. The researcher would like to examine the relationship between grades and amount of time on Facebook.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
18. To examine the effect of sleep deprivation on motor- skills performance, a sample of
n
= 10 participants was tested on a motor-skills task after 24 hours of sleep deprivation, tested again after 36 hours, and tested once more after 48 hours. The number of errors on the motor-skills task was measured.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
19. Ryan and Hemmes (2005) examined how homework assignments are related to learning. The participants were college students enrolled in a class with weekly homework assignments and quizzes. For some weeks. the homework was required and counted toward the student’s grade. Other weeks. the homework was optional and did not count toward the student’s grade. Predictably, most students completed the required homework assignments and did not do the optional assignments. For each student. the researchers recorded the average quiz grade for weeks with required homework and the average grade for weeks with optional homework to determine whether the grades were significantly higher when homework was required and actually done.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics:
20. Ford and Torok (2008) found that motivational signs were effective in increasing physical activity on a college campus. In a similar study, researchers first counted the number of students and faculty who used the stairs and the number who used the elevators in a college building during a 30-minute observation period. The following week, signs such as “Step up to a healthier lifestyle: and “An average person burns 10 calories a minute walking up the stairs” were posted by the elevators and stairs and the researchers once again counted people to determine whether the signs had a significant effect on behavior.
a. IV:
DV:
b. Null:
Alternate:
c. Descriptive statistics:
d. Inferential statistics: