First you might want to start with a working hint. Because I'm not sure if the _value gives valid output.
_value = enemy knowsAbout myguy
hint format ["Value: %1",_value];
If you get that working, you could try the following.
_value = enemy knowsAbout myguy
titleText [format ["Value: %1",_value],"PLAIN"];
As far as I know, this should work.