Suppose that a researcher conducts a study to see how level of anxiety ( *A1* = low, *A2* = medium, *A3* = high) predicts exam performance ( *Y*). The performance ( *Y*) and anxiety ( *A*) data are already entered into **u08a1data.sav**. Your task is to correctly enter the dummy codes to run regression. First, for dummy-coded regression, assume that the researcher wants to compare the medium anxiety group to the low and high anxiety groups. Enter the dummy codes for the low anxiety group contrast ( *D1*) and the high anxiety group contrast ( *D2*). Next, generate orthogonal codes for a positive linear trend ( *O1*) and a quadratic (curvilinear) trend for an upside-down U ( *O2*).

Use the DAA Template located in the resources to write up your assignment. The deadline for submitting your work is 11:59 PM CST on Sunday of Week 8.

**Step 1**. Write Section 1 of the DAA. In Section 1 of the DAA, articulate your predictor variables, the outcome variable, and the scales of measurement for each variable. Specify the sample size of the data set.

**Step 2**. Write Section 2 of the DAA. Test the normality assumption of multiple regression with a visual interpretation of the *Y* histogram.

**Step 3**. Write Section 3 of the DAA. Specify a research question for dummy-coded regression. Articulate a null hypothesis and alternative hypothesis for the overall regression model. Articulate the null hypothesis and alternative hypothesis for each predictor. Next, articulate a research question for the orthogonal-coded regression. Articulate a null hypothesis and alternative hypothesis for the overall regression model. Articulate the null hypothesis and alternative hypothesis for each predictor. Specify the alpha level.

**Step 4**. Write Section 4 of the DAA.

- Begin with a brief statement reviewing the normality assumption; state your codes for the dummy-coded regression and the orthogonal regression.
- Next, paste the SPSS output of the Model Summary for the dummy-coded regression.
- Report
*R*,*R2*, and interpret this effect size. - Next, paste the ANOVA output.
- Report the
*F*test and state your conclusion regarding the null hypothesis. - Next, paste the Coefficients output.
- Interpret the
*b*coefficients (i.e., what do the*b*values represent?) For each*b*coefficient, report the*t*tests and*p*-values, and for*D1*and*D2*, a statement regarding the null hypothesis. Report the squared semipartial correlations for*D1*and*D2*with an interpretation of effect size. - Next, paste the SPSS output of the Model Summary for the orthogonal-coded regression.
- Report
*R*,*R2*, and interpret the effect size. - Next, paste the ANOVA output.

## “Is this question part of your assignment? We Can Help!”

the researcher was first posted on March 25, 2020 at 1:55 pm.

©2019 "Nursing Researcher". Use of this feed is for personal non-commercial use only. If you are not reading this article in your feed reader, then the site is guilty of copyright infringement. Please contact me at admin@nursingresearcher.com