General instructions. This assignment is to be done in your lab session. Submit your assignment from the lab computer during lab time. If the assignment involves SPSS, be sure that when you open SPSS, you set it so that commands are displayed in the output: Edit -> Options, Viewer tab, check box Display commands in the log.

Open a blank Word document for typing up your answer. Include your name and username at the top.

Consider the data below. "Y" is the dependent measure, and "Xmag" is the independent variable that is measured on an interval (not nominal) scale.

Y   Xmag
4   1
5   1
6   1
1   2
2   2
3   2
2   3
3   3
4   3
6   4
7   4
8   4

* In SPSS do Analyze -> Compare Means -> Oneway ANOVA, with cubic polynomial contrasts selected. Include the ANOVA table in what you turn in (i.e., copy and paste it into your Word document).

* Expand your data table by typing in explicit polynomial contrast codes for linear, quadratic and cubic trends. Call these variables X1, X2 and X3. Run Analyze -> Reports -> Case Summaries and include the table of data in what you turn in.

* Run Analyze -> Regression -> Nonlinear to fit this Full model: Y = B0 + B1*X1 + B2*X2 + B3*X3. Include the ANOVA table in what you turn in, and explicitly point out what number in that table corresponds to the error (E_F) of the Full model, and also explicitly state the values for df, N, and #parameters.

* Run Analyze -> Regression -> Nonlinear to fit this Restricted model: Y = B0 + B1*X1 + 0*X2 + B3*X3. (Be careful to delete the B2 parameter from the list of parameters.) Include the ANOVA table in what you turn in, and explicitly point out what number in that table corresponds to the error (E_R) of the Restricted model, and also explicitly state the values for df, N, and #parameters.

* From the last two parts, construct an F ratio. Be explict about what terms (E, df) define the F ratio and the values that you are substituting in for those terms. State what the F ratio refers to, in terms of linear, quadratic, or cubic trends. Does that match anything in the Oneway ANOVA of the first part? If so, state explicitly what it is.

Submit your Word document to the Oncourse Assignment for this week. (Save a copy for your own records.)