Create a rubric for evaluating speaking and listening. Your rubric consist of columns with criteria for evaluation and rows of scores, from the lowest, 1, to the highest, 5. It should include these elements:
comprehension
clarification
fluency of response
accuracy of response
score
1
2
3
4
5
Create a set of 10 questions that a traveler might be asked when entering the country, such as length of stay, purpose of trip, people and places visiting, money and possessions on person and so on. Your questions must require an informative answer. Your 10 original questions should also include a few follow-up questions.
Train your evaluators in the use of your scoring rubric. You should fill out the example by providing explanations for each score under each category. For example, a score of 1 under fluency of response might read, "consisted mostly of hesitiations, mis-starts, and blank stares." Before administering your test to students, have the "customs officer" practice her role.
Record the test to video for future reference and to aid your evaluators. This could also serve as a great teaching tool for follow-up lessons, as it will build the student's awareness of his speaking and listening.