GIVE AN EXAMPLE OF A VARIABLE THAT YOU FEEL CAN BE RELIABLY MEASURED,
THEN GIVE AN EXAMPLE OF A RELIABLE MEASURE OF THIS DATA.

mango1952-ga,
An example of a variable that can be reliably measured is temperature.
 There is a variety of ways that you can measure temperature, the
simplest being using a thermometer.  Although the thermometer may
alter the temperature of what you are measuring by a slight amount,
this amount is negligable in the end. For example, my thermostat, a
type of thermometer, reads 23.3 C right now.  That is a fairly
accurate (to 1 decimal place) of the temperature in my house.

Another example of a variable that can be reliably measured is time.
Time can be measured using a stopwatch, or, if you really want
accuracy, a computer clock, or if you have access to one, an atomic
clock. We use clocks to measure time all the time.  An example of time
being measured with a clock would be right now, it is 1:43 AM where I
am.  Exactly 3:54 seconds have elapsed since I began typing this
answer.

Hope that helps.

-Tox-ga

Another variable that can be measured with precision is weight or
mass. This can easily be done with the use of an analytical electronic
balance.