In order to design an experiment you need a about the scientific question you are trying to answer

a. decision
b. procedure
c. hypothesis
d. conclusion

i guess that visual aids present persuasive examples to what you are presenting, some factors would be theme (does it fit with the color, information, what you are presenting), size (can you see it, is it a big enough span of data/information), and overall look of the visual aid.

hope this : )

are there answer choices to this question? this seems like a question where you have options to choose from.

layers of the earth affect the waves and these effects are seen on instruiments such as seimometers

compass can be used day and night, cloudy or sunny