Research Design Help: Measuring the effects of plagiarism intervention (Background: I am a full-time EFL instructor at a university in S. Korea. I want to do independent research, as most faculty would not be interested to collaborate with someone who only has an MA.)

Korea is known as the plagiarism capital of the world. Since I work with student writers there, I am very interested in the subject. I am trying to devise a research project which can measure the efficacy of plagiarism intervention strategies, namely teaching paraphrasing, summarization, and citation skills. I have done a small literature review and have ideas for getting student perspectives on plagiarism using already validated surveys. However, since I want to focus on effect, I was wondering if anyone had suggestion on how to actually measure this?

I was thinking some kind of pre-test/post-test, but would really love some more ideas.

Edit: to expand on the pre-test/post-test idea, I had thought about giving them a number of short paragraphs which they would need to paraphrase and cite correctly (assuming paraphrasing is a vital referencing skill) pre-intervention and then post.
I am just improvising on the fly here but does Korea have software like TurnItIn which measures (in a few different ways) the level of plagiarism in a particular paper or a set of papers usually from online sources. 

If you do, then you could think about devising an experiment where, in a class, you inform the students that you will be trying to reduce their "plagiarism tendencies" and take a pre-test perceptions survey. Next, you set a particular class paper as an assignment and note the different measurements on TurnItIn (or equivalent). Then, you make your intervention (in whatever form you choose) and finally set another class paper as an assignment and note the different measurements on TurnItIn this time. Finally, you set a post-test debriefing and follow up survey.

I think this would make for a very nice repeated measures model (from the TurnItIn or equivalent data) and some nice latent variable analysis from your surveys.

I hope this helps you in some meaningful way.