Option 1: Replicable simulation given a seed value
When you press the Update button the first time, it
will draw a random sample based on the INPUT values. The random sample
will be drawn given the seed value included in the text
box for seed value (default is given as 12345).
In the next step, you may wish to alter the inputs again OR keep the
inputs unaltered and press the Update button again.
This will conduct a second random sampling conditional on the given
INPUT values.
For example, reload the app for Normal distribution. Keep all the
INPUT values at its default values including the seed value as 12345.
Click the Update button THREE times. Note the Sample
Mean and SD displayed in the plot on the right (see the app). Three
successive values displayed should be as follows:
- On the first click of ‘Update’: x̄ = 20.07, s = 4.55
- On the second click of ‘Update’: x̄ = 18.13, s = 3.88
- on the third click of ‘Update’: x̄ = 19.43, s = 4.09
Since we generated the sample from a pre-specified seed value (here
12345, but you can change it to any value), these outcomes are
replicable. That means if you reload the app and do it again, you will
get the identical three values of x̄ and s of the sample in successive three
clicks. In other words, if you and your friend run the app together with
the identical seed value and other input values, both will get identical
estimates.
Option 2: Non-replicable instant simulation
If you wish to explore many scenarios and do not necessarily wish to
replicate your outputs, then select the option: Check the box to
update instantly. The important difference here is that you
cannot obtain multiple outcomes for the same input values as in Option
1. You have to change the input values (at least a minor change) to
trigger the app to sample data again. In other words, the app in this
option only ‘reacts’ when you change the INPUT values. Also, note that
the Update button will not respond in this
option and the random sampling will not be conducted using the seed
value (as in Option 1). In Option 2, the seed value is instantly set
based on the current time and process id, therefore, outputs are not
replicable.