Technical testing effort can differ from functional testing effort

The availability of a Button on a website itself can be based on many things....


-          Constraints
-          Role / Access
-          Combination (only after field 6 is filled-in), or only when ‘after date 27-8-2015’, or some other requirements...


Many people think. 'Okay, so there are i.e. 3 parameters, which leads to 2n is 2x2x2 = 8 possible combinations inwhich the button, might or might not, be visible on the website. (button available yes/no)
And they stop thinking there.
But in reality, when you process to the next stage.... (think further) in functional testing it can lead to many many more different paths....

I drew out an example:

The main things here are:

The possible combinations that we can think of, and the actual real ammount of possible combinations that there are in the software may differ. It can be because of many reasons. Bugs, added requirements, changed code, things that we first did not take into account, etc, etc,

The second important thing here is:

Technical and Functional Testers may have a different kind of view / aspect on things. Their focus can be 'not in line'.... so communication about understanding and getting 'the whole picture' is important.