Welcome to the first ever examination on Rasch Dichotomous analysis in UKM Faculty of Medicine. Please make sure that you have installed Bond and Fox Steps or Winsteps prior to doing this assignment.

Use your browser to download your Rasch data for this assignment from the following link;

• http://www.palmx.org/drtamil/2022/Jul2022/mactricno.txt
• If your matric number is P20627, then download your Rasch data from;
  http://www.palmx.org/drtamil/2022/Jul2022/P20627.txt

Do the following analysis on the data using “Bond and Fox Steps” or Winsteps then submit your answers via the LINK emailed to you before 10.30am 7th July 2022.

Scenario: Every semester, the ability of postgrad students on statistics are assessed using 30 OBA questions. To ensure the questions are reliable and able to discriminate good from poor students, reliability analysis are conducted on it regularly.

1. Open the given data using BNFSteps/WinSteps and press Enter twice. Let it generate the Fit Statistics. Look at the Infit results for both Person and Item. Is it acceptable? Copy and paste the table into your Word file.
2. Click on Plots>Bubble Plot. Select type “Infit” and display marker by “Label”. Interpret the results. Copy and paste the plot into your Word file.
3. Generate the Wright Map (Variable Maps). Zoom out so the entire map fits your screen, printscreen and paste the image into your Word file. Interpret the results accordingly. Answer the questions given in the Google Form.
4. Generate the Person Measures table (Table 17). Confirm your earlier answers of most able and least able students. Zoom out so the entire table fits your screen, printscreen and paste the image into your Word file. Are there any Infit ZSTD values larger than 2.0? Remember that ZSTD for Infit is supposed to be 0.
5. Generate the Item Measures table (Table 13). Zoom out so the entire table fits your screen, printscreen and paste the image into your Word file. Are there any Infit ZSTD values larger than 2.0? Remember that ZSTD for Infit is supposed to be 0. Look at the point measure correlation, which questions were unable to discriminate good from poor students (r<0.32).
6. Generate the Summary Statistics for All Persons & Items. Zoom out so the entire table fits your screen, printscreen and paste the image into your Word file. Determine the following;
   • Determine the KR-20 reliability index of the questions.
   • Compare the mean logit of Person Ability and Item Difficulty. Calculate the P(theta). The questions are Easy or Difficult for this group of students?
   • The students can be divided into how many groups? Show the calculation.

Upload your Word file into the Google Form, using your matric number (i.e. P20627) as it’s filename.

Just in case your answers go missing in the ethers of cyberspace, please email the above Word document file (e.g. P20627.doc) to statsexam@gmail.com, using your matric number (i.e. P20627) as its’ subject header.

Deadline 10.30 am 7th July 2022. After that time, no more submissions will be accepted.