Hello Vahid Norouzi Larsari ,

You can use a (one group pretest posttest design) with your class.

It would be an intact class (where there is no randomization but is still quasi-experimental).

Let me help you through the procedure:

1. you give them a pretest on the language activity you intend to teach.

2. You start your treatment (4 weeks or depending on your objectives)

3. You give them a posttest (it could be the same or a test that is equally difficult)

4. Then, you run a paired-samples t-test to compare the means of the pre-test and post-test. This will allow you to check for the gains of the experiment.

As for the language component, you can opt for vocabulary or grammar.

Abdelaziz Agrram Thanks for your answer. I will be so gald if you can help me for doing my research.

My supervisor said that How your groups are comparable before treatment? here I am so confused, how can I understand these groups are comparable?

Also, dr Agrram, how can I select the participants based quasi? the sampling will be convience samoling? I want to select the participants from an English language center and their level is elementary? then, is it necessary to homogenize their level of proficiency?

Do not assign students to groups. You should work with groups as they are (intact classes).

If you have the choice of assigning students from the center to experimemtal and control groups, you can use randomization. Howver, by randomly assigning participants, your design will be true experimental, not quasi-exp.

As for the comparability, you can do it by comparing their scores in the pretest (compare the means for the two groups). On a final bote, their means should be equal.