# CTC Conducting an Independent Project

As in prior modules, students should read the Green and Salkind lessons and practice working the lesson examples in SPSS. Students should read the instructions and grading scheme on the attached document and submit their labeled SPSS output as an attachment to this assignment.

SPSS Assignment Lesson 24: Conducting an Independent -Samples t Test

The goals of this SPSS assignment are for students to work with data sets in SPSS, conduct an

independent-samples t test on the data, identify results of the analyses on SPSS output, and correctly

interpret these results. To achieve these goals, students will perform the computations outlined in selected

Lessons of the Green and Salkind (2017) textbook in SPSS and will label their output for submission.

For this assignment, students will perform the SPSS analyses that are described in Lesson 24 of the Green

and Salkind text. As instructed in the text, students are to download the “Lesson 24 Data File 1” and

complete each analysis as explained in the text.

Students are to follow along with the step-by-step instructions provided in Lesson 24 and perform each

analysis in SPSS. After performing the independent-samples t test analyses in SPSS as stated in the text,

copy the SPSS output file and paste it into a Word document. Save the Word document to your own

external media (e.g., flash drive) if you are working on a University computer, or save the Word document

to your own computer’s hard drive even if you have SPSS installed on your computer. By saving your

output file as a Word document (and data file as an Excel file, see Lesson 6), you can finalize your

assignment and view your work even when you do not have access to a computer with SPSS (e.g., when

working on a University computer then finishing the assignment at home, when checking your grades on

a different computer, in later semesters when you need to remember how to read SPSS output but your

SPSS license has expired, when traveling during the semester).

After saving the SPSS output to Word, insert text boxes on the output beside each analysis requested

below. Draw a line connecting the text box to the specific SPSS data point you are labeling. Inside each

text box, label the relevant output using the number and wording as stated below. For example, on your

Word document of SPSS output, next to the t test data boxes, label the appropriate output with a textbox

that reads “1. Mean percentage of talk time for the low stress group” and so on for each analysis

requested.

On your SPSS output, insert a textbox next to each element in the output and label the following

information. Each of these elements is worth two (2) points apiece, except where noted.

1. Mean percentage of talk time for the low stress group

2. Mean percentage of talk time for the high stress group

3. Mean difference of talk time between the low stress and high stress groups [include the

calculations of this value in the textbox as well] (3 points for this item)

4. Degrees of freedom for the t test assuming homogeneity of variance [include the formula to

compute the df in the textbox as well] (3 points for this item)

5. The probability value for the equality of variance test

6. The probability value for the t tests

Insert a textbox at the bottom of your output and explain each of the following points. Each of these

elements is worth three (3) points apiece. Combined, all elements total 20 points for the assignment.

7. Explain the outcome of the test for homogeneity of variance and which t test you should report.

8. Explain whether the value of the t test is statistically significant or not. Phrase your explanation in

terms of your decision regarding the null hypothesis.

After you have labeled your output as requested above, save the Word document again and submit the

Word document that includes the labeled t test output as an Assignment. Only Word documents that have

been appropriately labeled will be accepted for credit.

Word documents that are not labeled will not receive credit. Without labels, there is no evidence that

students have examined the output, and there is no evidence that students can interpret the output. To meet

the goals of this assignment as stated above, it is not sufficient that students are able to generate SPSS

output. Numbers and tables on a page are meaningless unless one knows how to interpret them properly.

Thus, unlabeled submissions will not receive credit.

Likewise, labels that are not clearly linked to a specific data point on the SPSS output will not receive

credit. I allow flexibility in linking labels to output. Students may insert lines connecting the label and

data point (preferred), or students may use color coding to identify which label belongs with which data

point (i.e., use the same color of highlighting for a label and its output, then use a different color of

highlighting for another label and its data point). As long as your work is easy to read and clearly labeled,

I will accept a variety of “design choices.” Therefore, feel free to be creative and make a document that

will best help you now and in the future. However, I will not credit work I cannot read, so be sure your

lines are not overlapping or convoluted and be sure your color choices are not so dark that they obscure

the text and so on… Though I allow flexibility in linking labels with output, I will not scroll through a

document looking for a label or data point. Thus, the textbox must be inserted next to, or at minimum, on

the same screen as the output box. Feel free to develop a labeling technique that works for you; just be

sure it can be easily and unambiguously understood at first glance.

Finally, do not submit SPSS output files even if they are labeled. You will be unable to open these files

without the SPSS program, making them potentially unhelpful to you in the future (e.g., when reviewing

for your exit exam). Save the SPSS output as a Word file so you will be able to reference the information

at a later date regardless of your access to SPSS.