SETI researchers do not expect to find recognizably designed messages
in the signals they are looking for; in fact, they expect that the
signal modulation would be smeared out and lost. They are looking for
narrow-band signals, which are what people build and are not found in
known natural radio signals (SETI Instutute n.d., Shostak 2005). The
objective criterion for recognizing intelligent design is to look for
things that look like what people build.
The SETI Institute itself recognizes "Intelligent Design" as
creationism with no scientific value (DeVore 2005).