Distance or Time?

I'm hoping to do my experiment before the holidays end. It should take no longer than a day if I can get all 15 males and females over (most likely church friends). I'll also need to get all the teenagers (anyone under 18) to get their parents to write me a note saying that they are allowed to take part in the experiment, or I could write one up and have them sign it. For now i'm going to do some more research on reflex actions and the ruler drop

This experiment is based on the subjects' reaction time, so is this one but it also has a reaction time table to convert your measurement in cm to a reaction time in seconds. This website has a formula that I can use to convert the distance on the ruler to a reaction time. So now i'm thinking that maybe I can use time as one of my variables, hopefully this formula is accurate. What do you think Ms Zhang?

My Experiment

Aim: To find out which gender has faster reflex actions

Hypothesis: Males have faster reflex actions than females

Independent Variable: Gender

Dependent Variable: Length (cm)

The experiment will be repeated three times for each test subject and there will be 15 males and 15 females.

I want to make sure this is a legit experiment before I go ahead and do it and that both my variables are right in relation to the experiment, so if you could let me know once you've seen this Ms Zhang. Thankyou!

the ruler drop

Ms Zhang was telling me to have a look at facial reflex actions but i'm not quite sure how I would test that. So far I'm just thinking that the ruler drop test would be my best bet. And since it's a quick experiment I don't think it would be smart to have 'time' as one of the variables, I thought 'distance (cm)' would be better. As in, how many cm have passed before the subject has grabbed the ruler