Edps 557 quiz 4 (2019)


Part 1

  1. A variable that has a relationship with (in terms of covariance), or has the potential to be related to the outcome variable we’ve measured, is
  2. Which of the following sentences best describes a covariate?
  3. Which of the following assumptions must be met when conducting an ANCOVA?
  4. ANCOVA is:
  5. What are the two main reasons for including covariates in ANOVA?
  6. In the context of analysis of covariance, this is the value of the group mean adjusted for the effect of the covariate.
  7. A researcher is interested in examining individuals’ attitudes toward three computer programs. Each participant rates one of three programs. The researcher controls for previous experience with computers. This could utilize:
  8. Participants were randomly allocated to one of two stress management therapy groups, or a waiting list control group. Their baseline levels of stress were measured before treatment, and again after 3 months of weekly therapy sessions. The researcher decided to run an ANCOVA on her data. What was the covariate?
  9. A health psychologist was interested in the effects of vitamin supplements on the immune system. Three groups of adults were exposed (in a highly ethical way) to the cold virus; one group took no supplements for a week before exposure, another had vitamin C supplements, and a third had multivitamins (excluding C). The severity of the cold was measured as a percentage (0% = not contracted, 100% = very severe symptoms). The psychologist also measured the number of cigarettes that each person smoked per day, as smoking suppresses the immune system. The psychologist was interested in the differences in the severity of the illnesses across different vitamin groups accounting for cigarette usage. What technique should be used to analyze these data?
  10. You are conducting a study. The IV is attachment style. There are three groups of individuals with different attachment styles; these are secure, dismissing, and fearful. You want to explore whether these differ on their scores of relationship satisfaction. The DV is relationship satisfaction. You are aware, however, that relationship satisfaction is known to covary with depression. You conduct an ANCOVA with this data. The formula will remove the variance due to the association between which two variables?
  11. Imagine we wanted to investigate the effects of three different conflict styles (avoiding, compromising and competing) on relationship satisfaction, but we discover that relationship satisfaction is known to covary with self-esteem. Which of the following questions would be appropriate for this analysis?

Part 2 

A marketing manager was interested in the therapeutic benefit of certain soft drinks for curing hangovers. He took 15 people out on the town one night and got them drunk. The next morning as they awoke, feeling dehydrated, he gave five of them water to drink, five of them Lucozade (a very nice glucose-based UK drink) and the remaining five a leading brand of cola (this variable is called drink). He measured how well they felt (on a scale from “0 = I feel like death” to “10 = I feel really full of beans and healthy”) two hours later (this variable is called well). He wanted to know which drink produced the greatest level of wellness. However, he realized it was important to control for how drunk the person got the night before, and so he measured this on a scale of “0 = as sober as a nun” to “10 = flapping about like a haddock out of water on the floor”(this variable is called drunk). The data are in the file HangoverCure.sav under Resources for Quizzes >> Quiz 4. Conduct an ANCOVA to see whether people felt better after different drinks when controlling for how drunk they were the night before. Let’s identify type of variables in the data to conduct data analyses.

Let’s run an ANOVA WITHOUT the covariate using the HangoverCure.sav in SPSS. You will have the SPSS output as below when the covariate is not included.  

Before including a covariate in an analyses, we should check that the covariate is independent from the experimental manipulation (NO INTERACTION). In this case, we need to check out that the proposed covariate (CV) is roughly equal across the levels of our independent variable (IV). We can test this by running an ANOVA using SPSS, with the proposed covariate (CV) as the outcome and the independent variable (IV) as the predictor. You will have the SPSS output as below that shows the results of the one-way ANOVA.  

Next, we can conduct the ANCOVA in SPSS: [Analyze] – [General Linear Model] – [Univariate…].

· First, specify the variables for Dependent Variable (DV), Fixed Factor(s) (IV), and Covariate(s).

· Second, click on [Options] to assess the Options dialog box. Then, check on Descriptive Statistics, Estimates of effect size, Parameter Estimates, and Homogeneity tests.

· Next, click on [Contrasts…] to assess the Contrasts dialog box. Then, Change the type of contrast from None to Simple, and Change Reference Category from Last (which is default) to First.

· Finally, click on [Continue] to return to the main dialog box and click on [OK] in the main dialog box to run the ANCOVA.

· Among the tables in the SPSS output, what does Leven’s Test of Equality for Error Variances inform us?

According to the ANCOVA table below, which of the following statements best reflects what the effect of the type of drink tells us? 

According to the ANCOVA table below, which of the following statements best reflects what the effect of drunkenness tells us?

The SPSS output below shows the Parameter Estimates that are calculated using a regression analysis with drink split into two dummy coding variables. Here, the beta values literally represent the differences between the means of the drink groups and so the significances of the t-tests tell us whether the group means differ significantly. First, identify which drink was coded as a reference group in the comparisons. 

Based on the SPSS output below on the Parameter Estimates, we can conclude as below. 

The SPSS output below shows the descriptive statistics and the adjusted values of the group means. While the descriptive statistics shows no mean differences in X and Y drink groups, the adjusted means show that the significant ANCOVA reflects a difference between the X and Z groups. 

The SPSS output below also shows the effect sizes in terms of partial eta squared calculated using sums of squares for the effect of drink, drunk, and the error. Now we can report the main findings as follows. Report three decimal places for F, p, and partial η2 values.

US Custom Writers
Calculate your paper price
Pages (550 words)
Approximate price: -

Why Work with Us

Top Quality and Well-Researched Papers

We always make sure that writers follow all your instructions precisely. You can choose your academic level: high school, college/university or professional, and we will assign a writer who has a respective degree.

Professional and Experienced Academic Writers

We have a team of professional writers with experience in academic and business writing. Many are native speakers and able to perform any task for which you need help.

Free Unlimited Revisions

If you think we missed something, send your order for a free revision. You have 10 days to submit the order for review after you have received the final document. You can do this yourself after logging into your personal account or by contacting our support.

Prompt Delivery and 100% Money-Back-Guarantee

All papers are always delivered on time. In case we need more time to master your paper, we may contact you regarding the deadline extension. In case you cannot provide us with more time, a 100% refund is guaranteed.

Original & Confidential

We use several writing tools checks to ensure that all documents you receive are free from plagiarism. Our editors carefully review all quotations in the text. We also promise maximum confidentiality in all of our services.

24/7 Customer Support

Our support agents are available 24 hours a day 7 days a week and committed to providing you with the best customer experience. Get in touch whenever you need any assistance.

Try it now!

Calculate the price of your order

Total price:

How it works?

Follow these simple steps to get your paper done

Place your order

Fill in the order form and provide all details of your assignment.

Proceed with the payment

Choose the payment system that suits you most.

Receive the final file

Once your paper is ready, we will email it to you.

Our Services

No need to work on your paper at night. Sleep tight, we will cover your back. We offer all kinds of writing services.


Essay Writing Service

No matter what kind of academic paper you need and how urgent you need it, you are welcome to choose your academic level and the type of your paper at an affordable price. We take care of all your paper needs and give a 24/7 customer care support system.


Admission Essays & Business Writing Help

An admission essay is an essay or other written statement by a candidate, often a potential student enrolling in a college, university, or graduate school. You can be rest assurred that through our service we will write the best admission essay for you.


Editing Support

Our academic writers and editors make the necessary changes to your paper so that it is polished. We also format your document by correctly quoting the sources and creating reference lists in the formats APA, Harvard, MLA, Chicago / Turabian.


Revision Support

If you think your paper could be improved, you can request a review. In this case, your paper will be checked by the writer or assigned to an editor. You can use this option as many times as you see fit. This is free because we want you to be completely satisfied with the service offered.