New!  Scrambling of multiple-choice answers on PDFs

Problem Attic can create up to five versions of a document by scrambling multiple-choice answers. You will see the new option if you create or open a document, go to Make PDF, and click the Advanced button.

Here’s what you need to know about the new scrambling option.

• After clicking Download, it can take up to a minute for the zip file to be created. Do not leave the page. When downloading is complete, you will see the message in your browser.

• The zip will contain a csv file for each version of the test. The csv is intended to help with scoring. It will have answers and other test metadata.

• Because the csv files have scoring information, you may not need the answer key which is normally at the end of a PDF. If you are going to distribute the PDFs electronically (instead of printing them), then you should probably not include the key.

• The scrambling option is for multiple-choice questions only. It won’t affect other question types, like multi-select. Also, the option will not affect questions for which scrambling is turned off in the editor.

• The seed controls scrambling. For each download, a random value is generated. Usually there is no reason to enter a different value. If, however, you’ve edited a question or changed document formatting, and you need to reproduce the scrambling in a prior job, then you can enter that job’s seed.

Technical information

The seed value is always shown in the csv file that goes with a PDF. This is for your convenience, in case you have to re-download a document and you want the scoring information to stay the same. Simply type the seed in the Advanced dialog and click the Download button again.

Please note that the seed is “deterministic”. For a given value, multiple-choice answers will be scrambled the same way no matter how many times you download a document—provided you don’t make any significant changes to the document. If you add, remove or re-arrange questions, then you will get different scoring information. This is true across the document and for individual questions, even if you enter the same seed as before.

If you download more than one PDF document in a zip file, then each will have its own seed. This is what causes the scrambling to differ. The first document that Problem-Attic creates will use the seed that is shown in the Advanced dialog. Then, for each subsequent document (up to five), the seed will be incremented by one. For example, if the seed for “Form 1” is 5943, then the seed for “Form 2” will be 5944. Keep this mind if you want to reproduce just one out of several documents. Use its particular seed, as shown in the csv file that goes with it.

Seed values are randomly generated by Problem-Attic and meaningless on their own. Any number from 1 to 99,999 is valid, and for scrambling purposes, larger numbers are no better than smaller numbers. The main idea is that they should differ for a set of documents if you want unique answer keys.