A lot of studies use "pre-", "post-" and "delayed-post" in order to discern if the skill was learned via the treatment (i.e., an immediate post-test, not long after the lesson or learning activity) and to see if it was "acquired" or remembered after a period of time. The delayed posttest varies quite a bit from what I've seen, but it would be worth checking some other similar studies.

Thank you, Ryan Spring ! The “delayed-post test” is also called “follow-up test”, if I am not mistaken.

Thank you very much, Farhad Tabandeh

I fully agree with Farhad's answer and suggestions!

Yes, I also fully agree with Farhad's answer and suggestions. Ultimately, the test will show exactly what it has measured. So researchers will have to decide what they want to look at. If the pre- and post-test are put directly before and after the treatment (i.e., teaching), they will show just that - what the treatment has taught the learners (and this includes what the pre-test has taught the learners). Any waiting period after the treatment will also measure decay (i.e., forgetting), in addition to what has been learnt in the treatment and pre-test. Unless of course learners have been experiencing or practicing the teaching contents again on their own or in a different course setting after the treatment.

Modification in the use of language is more about the acceptance of the individual who is using it. As you have mentioned in your question 'just polite requesting' - it would also depend on the individuals being trained on it, that how proficient they have become after how many hours of training/practice.

Ideally, the pre-test happens before the training & the post-test immediately after.

This will depend on the type of pre-test and post-test being administered and the objectives of the test. Generally, a period of at least two weeks is recommended to allow for sufficient learning and practice time between the two tests.

Well as a standard procedure in experimental research designs, just before the start of the treatment you're gonna have your pretest, and just after the treatment the posttest should be carried out. Hence, the interval btw pre and posttest depends on your treatment. However, most researchers believe that this interval SHOULD NOT BE LESS THAN A MONTH, obviously because we don't want our participants to memorize the test items. If it is longer than this, you're good to go.

Good luck. Monika Zapletalová

Well as a standard procedure in experimental research designs, just before the start of the treatment you're gonna have your pretest, and just after the treatment the posttest should be carried out. Hence, the interval btw pre and posttest depends on your treatment. However, most researchers believe that this interval SHOULD NOT BE LESS THAN A MONTH, obviously because we don't want our participants to memorize the test items. If it is longer than this, you're good to go.

Good luck. Monika Zapletalová

Dear Colleague,

This is a good question!

Since the test is about teaching English as a Foreign Language with the content of the intervention is "just" polite requesting. Attention should be attached to the following two aspects:

(1) Test items type: Is it a test of multiple choice questions or short answer questions? If it is an objective test of 20 or 30 multiple choice questions, the interval may be longer, say, two weeks or so. If it is a test of short answer questions or an essay question, the interval may be shortened to one week;

(2) Test effect

If test effect is put into consideration, the time interval btw pre- and post-test should be no more than 3 days. The reason is simple: during those three days, the general proficiency of the students, statistically, will not have significant changes.

Hello, this depends on your experimental approach. If you are implementing aids for understanding a foreign language, the interval between the pre and post-test should be one week. Otherwise, if it is a question of implementing ludic activities, it will take from three to six months to do the post-test. Good luck for the future.