Strategy Tester specific data used

 

When testing out my EA over various periods of time, the strategy tester will say testing M15, testing M5, testing M1 and then start running my EA.

I'm wondering on what basis does it decide what data to use as your test data? For example my OnTick() data will be different if it uses M15 as opposes to M1?

Also is this related to historical data? I've not much experience with the historical data or its use, is it precisely this? Strategy testing and offline charts etc?

 

UPDATE: it says collecting M15, M5, M1 and then Using M15, M5, M1. How does it decide which set to run my EA on?  

 

This was due to the settings of extern variables. Also, does the strategy tester take a while to recognise when a new version of a ex4 has been recompiled. My tester is using an old version and wont seem to change to the newest compiled version regardless of what variables i change. 

 

It uses the smallest available timeframe to generate ticks.

'Strategy Tester: Modes of Modeling during Testing' - MQL4 Articles