# Homework assignment 3 | PY216 | University of Alabama at Birmingham

**This assignment will cover the hypothesis testing method applied to differences between two groups. **It will test your ability to identify what type of analysis is appropriate for each scenario presented. Further, it will test your ability to conduct the appropriate analyses for each problem using SPSS and interpret the statistical output. You will need to use material primarily from labs 3 and 4 to complete this assignment.

**1.** The **Digit Span Backwards** task requires individuals to repeat a sequence of numbers in backwards order. The goal is to repeat as many numbers as possible. Fifteen older adults (aged 65+ years) with recent traumatic brain injuries were administered the Digit Span Backwards task when they entered a geriatric brain injury rehabilitation program. The same fifteen older adults were *re-administered *the task on their last day of rehabilitation treatment. **A rehabilitation psychologist wants to know if the older adults had ****improvements**** in their Digit Span Backwards scores after treatment.** The data (participant ID, initial digit span score, and final digit span score) are stored in an Excel file called **Digit Span Backward.xlsx**

**a.** Enter your data into SPSS. Remember to give your variables __names and labels__ of your choice that SPSS can recognize. Save this dataset file (.sav) to a file name of your choice. __Upload this data file (.sav) to Canvas when you submit your assignment.__ (**1 point**)

**b.** What kind of analysis should you perform to determine whether there are differences in the **Digit Span Backwards** scores between the initial measurement and post-treatment measurement? In __full sentences__ describe the appropriate analysis to use and why it is appropriate. (**2 points**)

**c.** Will you use a 1- or 2-tailed test? Justify your answer in __full sentences__ (**1 point**)

(*hint*: use the wording from the paragraph describing the research scenario to answer this questions).

**d.** State your null and alternative hypotheses in __full sentences__. (**2 points**)

**H0: **

**H1: **

**e.** What are the mean and standard deviation for **Digit Span** scores at the initial and final administration of the task? State your answers in __full sentences__. (**1 point**)

**f.** In SPSS, perform the appropriate analysis on the difference between the initial and final **Digit Span Backwards** scores for the older adults with brain injuries. __Paste your SPSS output below__. (**2 point**)

**g.** Report the results from your analysis in __full sentences__ using APA format to report the test results (*t*(*___*)* = *__ *, p = * ___) and the confidence interval (95%CI[*lower bound value*, *upper bound value*]). (**2 points**)

**h.** In __ full sentences__, make your decision to reject or fail to reject the null hypothesis based on the p-value and the means reported in

**question e**(

*hint*: if this was a one-tailed test, make sure the difference you see is in the direction expected). Write a conclusion to the original research question in the scenario above. (

**2 points**)

**2.** A researcher has developed an intervention to improve the visual-motor coordination in children with autism. She randomly assigns thirty children with autism to one of two groups: **a control group**, in which the 15 children receive normal training intervention, and an **experiment group**, in which the 15 children receive a visual-motor coordination training intervention. **She wants to know if the children in the experiment group will have different hand-eye coordination scores than those in the control group**, so she gives them the Bender Visual Motor Gestalt Test and records the results. She saves data (with two variables; **group type:** 1- Experiment Group, 2 – Control Group and **hand-eye coordination** **test score**) from the two groups __in a file called ____ autism experiment.xlsx__.

**a.** Use the file, __ autism experiment.xlsx__ to import your data into SPSS. Remember to give your variables names of your choice that SPSS can recognize. Save this dataset file to a file name of your choice.

__Upload this data file to Canvas when you submit your assignment__. (

**1 point**)

**b.** What kind of analysis should you perform to determine whether there are differences in visual-motor coordination scores between the two test conditions (i.e., to test the difference between these two groups)? In __full sentences__ describe the appropriate analysis you used and why. (**2 points**)

**c.** State your null and alternative hypotheses in __full sentences__. (**2 points**)

**H0:**

**H1:**

**d.** What are the mean and standard deviation for Bender test scores (remember, this is the test of **hand-eye coordination**) for each group? Remember, you will have a mean and standard deviation for the control and experiment conditions. State your answers in __full sentences__. (**1 point**)

**e.** Perform the appropriate analysis on the difference between the control and experimental groups’ Bender Visual Motor Gestalt Test scores for the children with autism. __Paste your SPSS output below__. (**2 points**)

**f.** Report the results from your analysis in __full sentences__ using APA format to report the test results [*t*(___)* = *__ *, p = * ___] and the confidence interval (95%CI[*lower bound value*, *upper bound value*]). (**2 points**)

**g.** In __full sentences__, make your decision to reject or fail to reject the null hypothesis based on the p-value and the confidence interval (i.e., is there a significant difference between the groups in Bender test scores?). Write a conclusion to the original research question in the scenario above. (**2 points**)

I have attached the other parts that go to this assignment if you have any questions please let me know.