## PSY 520 Weekly Discussion Assignment Essays

### Week 1 Discussion 1

Review the levels of measurement terms in the Statistics Visual Learner media piece. Compare and contrast Stevens’s four scales of measurement, and explain when each type of scale should be used.

### PSY 520 Week 1 Discussion 2

The professor teaching a large introductory class gives a final exam that has alternate forms, A, B, and C. A student taking the exam using Form B is upset because she claims that Form B is much harder than Forms A and C. Discuss how percentile point data might be useful to determine if the student is correct.

### PSY 520 Week 2 Discussion 1

The process of random sampling guarantees that the sample selected will be representative of the population. Is this statement true? Discuss.

### PSY 520 Week 2 Discussion 2

Review the video on Normal Distribution in the Calculations section of the Statistics Visual Learner media piece. Bob compares his SAT Verbal score of 400 to Marge’s ACT Verbal score of 20. I beat you, he exclaims.

- My score is 20 times your score! Although his multiplication is good, his logic is faulty.
- Explain why.

### Week 3 Discussion 1

Review the video Linear Correlation in the Calculations section of the Statistics Visual Learner media piece.

It is sometimes said that the higher the correlation between two variables, the more likely the relationship is causal. Do you think this is correct? Discuss.

### Week 3 Discussion 2

Discuss the strengths and weaknesses of correlational and regression studies; discuss concepts such as positive and negative correlations, correlation coefficients, confounding, and causality.

### Week 4 Discussion 1

Explain why there is an inverse relationship between committing a Type I error and committing a Type II error. What is the best way to reduce both kinds of error?

### Week 4 Discussion 2

Review the term Significance Test in the Statistics Visual Learner media piece. When a newspaper or magazine article reports the results of a study and draws a conclusion without also reporting whether the results are statistically significant, what are the possible reasons for doing so? How seriously should you take the conclusion offered in such a study?

### Week 5 Discussion 1

Explain why using the t statistic may be an appropriate alternative to using a z-score (use the concept of estimated standard error to justify your answer).

### Week 5 Discussion 2

Discuss how the t-test for correlated groups and the t-test for single samples are alike and different.

### Week 6 Discussion 1

Review the four ANOVA videos in the Calculations section of the Statistics Visual Learner media piece. Explain the major differences between analyzing a one-way ANOVA versus a two-factor ANOVA, and explain why factorial designs with two or more independent variables (or factors) can become very difficult to interpret.

### Week 6 Discussion 2

Explain how the ANOVA technique avoids the problem of the inflated probability of making Type I error that would arise using the alternative method of comparing groups two at a time using the t-test for independent groups.

### Week 7 Discussion 1

Review the three Non-parametric test videos in the Calculations section of the Statistics Visual Learner media piece.

A researcher is examining preferences among four new flavors of ice cream. A sample of n = 80 people is obtained. Each person tastes all four flavors and then picks a favorite. The distribution of preferences is as follows. Do these data indicate any significance preferences among the four flavors Test at the .05 level of significance?

Ice Cream Flavor | |||

A | B | C | D |

12 | 18 | 28 | 22 |

### Week 7 Discussion 2

Is it true that parametric tests are generally more powerful than nonparametric tests? If so, give two reasons why you might choose to use a nonparametric test instead of a parametric test.

Week 8 Discussion 1

To determine whether a new sleeping pill has an effect that varies with dosage, a researcher randomly assigns adult insomniacs, in equal numbers, to receive either 4 or 8 grams of the sleeping pill. The amount of sleeping time is measured for each subject during an 8-hour period after the administration of the dosage. What type of design is this, and what type of statistic is needed to analyze the data?

### Week 8 Discussion 2

Dr. Bill Board designs a 2 X 2 between-subjects factorial design, where Factor A is word frequency (low or high) and Factor B is category cues (no queues or cues). Assume that the data are intervals. What type of statistic is needed to analyze the data? Probability Project Use the document “Probability Project” to complete the assignment.

While APA format is not required for the body of this assignment, solid academic writing is expected, and documentation of sources should be presented using APA formatting guidelines, which can be found in the APA Style Guide, located in the Student Success Center.

### Topic 3 – Probability Project

#### Directions

Use the following information to complete the assignment. While APA format is not required for the body of this assignment, solid academic writing is expected, and documentation of sources should be presented using APA formatting guidelines, which can be found in the APA Style Guide, located in the Student Success Center.

There are many misconceptions about probability which may include the following:

- All events are equally likely
- Later events may be affected by or compensate for earlier ones
- When determining probability from statistical data, sample size is irrelevant
- Results of games of skill are unaffected by the nature of the participants
- “LuckyUnlucky” numbers can influence random events
- In random event involving selection, results are dependent on number rather than rations
- If events are random then the results of a series of independent events are equally likely

### PSY 520 Wk3 Probability Project

The following statements are all incorrect. Explain the statements and the errors fully using the probability rules discussed in topic two.

- I have flipped an unbiased coin three times and got heads, it is more likely to get tails the next time I flip it.
- The Rovers play Mustangs. The Rovers can win, lose, or draw, so the probability that they win is 13.
- I roll two dice and add the results. The probability of getting a total of 6 is 112 because there are 12 different possibilities and 6 is one of them.
- Mr. Purple has to have a major operation. 90% of the people who have this operation make a complete recovery. There is a 90% chance that Mr. Purple will make a complete recovery if he has this operation.
- I flip two coins. The probability of getting heads and tails is 13 because I can get Heads and Heads, Heads and Tails, or Tails and Tails.
- 13 is an unlucky number so you are less likely to win raffles with ticket number 13 than with a different dumber.

### Wk5 Correlation And Regression Assignment

Use the attached document “Correlation and Regression” to complete the assignment. While APA format is not required for the body of this assignment, solid academic writing is expected, and documentation of sources should be presented using APA formatting guidelines, which can be found in the APA Style Guide, located in the Student Success Center.

This benchmark assignment assesses the following programmatic competencies 3.1

Interpret psychological phenomena using scientific reasoning.

#### Topic 5– Benchmark – Correlation and Regression Project

#### Directions

Use the following information to complete the questions below. While APA format is not required for the body of this assignment, solid academic writing is expected, and documentation of sources should be presented using APA formatting guidelines, which can be found in the APA Style Guide, located in the Student Success Center.

Select at least three variables that you believe have a linear relationship.

- Specify which variable is dependent and which are independent.

Collect the data for these variables and describe your data collection technique and why it was appropriate as well as why the sample size was best.

- Submit the data collected by submitting the SPSS data file with your submission.

Find the Correlation coefficient for each of the possible pairings of dependent and independent variables and describe the relationship in terms of strength and direction.

Find a linear model of the relationship between the three (or more) variables of interest.

Explain the validity of the model.

### Week 6 Exercise

Details:

Complete the following exercises located at the end of each chapter and put them into a Word document to be submitted as directed by the instructor.

Show all relevant work; use the equation editor in Microsoft Word when necessary.

- Chapter 16, numbers 16.9, 16.10, 16.12 and 16.14
- Chapter 17, numbers 17.6, 17.7, and 17.8
- Chapter 18, numbers 18.8, 18.11, and 18.12

### PSY 520 Topic 7 – MANOVA Project

Directions

Use the following information to complete the assignment. While APA format is not required for the body of this assignment, solid academic writing is expected, and documentation of sources should be presented using APA formatting guidelines, which can be found in the APA Style Guide, located in the Student Success Center.

A researcher randomly assigns 33 subjects to one of three groups.

Group 1 receives technical dietary information interactively from an on-line website.

Group 2 receives the same information from a nurse practitioner, while

Group 3 receives the information from a video tape made by the same nurse practitioner.

The researcher looked at three different ratings of the presentation; difficulty, usefulness, and importance to determine if there is a difference in the modes of presentation.

In particular, the researcher is interested in whether the interactive website is superior because that is the most cost-effective way of delivering the information.

Group | Usefulness | Difficulty | Importance |

1 | 20 | 5 | 18 |

1 | 25 | 9 | 8 |

1 | 23 | 15 | 20 |

1 | 16 | 9 | 22 |

1 | 20 | 6 | 22 |

1 | 28 | 14 | 8 |

1 | 20 | 6 | 13 |

1 | 25 | 8 | 13 |

1 | 24 | 10 | 24 |

1 | 18 | 10 | 20 |

1 | 17 | 9 | 4 |

2 | 28 | 7 | 14 |

2 | 25 | 14 | 5 |

2 | 26 | 9 | 20 |

2 | 19 | 15 | 22 |

2 | 29 | 14 | 12 |

2 | 15 | 6 | 2 |

2 | 29 | 10 | 5 |

2 | 26 | 11 | 1 |

2 | 22 | 5 | 2 |

2 | 15 | 15 | 14 |

2 | 29 | 6 | 4 |

2 | 15 | 6 | 3 |

3 | 22 | 8 | 12 |

3 | 27 | 9 | 14 |

3 | 21 | 10 | 7 |

3 | 17 | 9 | 1 |

3 | 16 | 7 | 12 |

3 | 19 | 9 | 7 |

3 | 23 | 10 | 1 |

3 | 27 | 9 | 5 |

3 | 23 | 9 | 6 |

3 | 16 | 14 | 22 |

### Week 8 Research: Question Project

Details:

In 1,250-1,500 words, answer the following questions about possible research options.

- Create a research question in the field of psychology that you are interested in researching. Write questions clearly. Include a brief background of the problem you are proposing and why it is important to the field of psychology.
- State the null and alternative hypothesis (in both words and statistical notation) need to address the research question.
- Choose which statistical test would be used to conduct the study and support it with research.
- Describe the type of data that needs to be collected to conduct the study and what techniques are best for collecting data.

Use three to five scholarly resources to support your explanations.

Prepare this assignment according to the guidelines found in the APA Style Guide, located in the Student Success Center. An abstract is not required.

This assignment uses a rubric. Please review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion. You are required to submit this assignment to Turnitin. Please refer to the directions in the Student Success Center.

#### PSY 520 Week 8 Exercise

Details:

Complete the following exercises located at the end of each chapter and put them into a Word document to be submitted as directed by the instructor.

Show all relevant work; use the equation editor in Microsoft Word when necessary.