HARRISBURG -- The superintendent of a school district that is defending its decision to discuss "intelligent design" in biology classes testified today that he did not equate the concept with creationism.

"I did not see intelligent design as creationism. I saw them totally separate," Dover Area Superintendent Richard Nilsen said. "Creationism references Genesis. ... Intelligent design does not reference a biblical context at all."

The Dover Area School Board approved the curriculum change a year ago, requiring students to hear a statement about intelligent design before ninth-grade biology lessons on evolution. The statement says Charles Darwin's theory is "not a fact," has inexplicable "gaps," and refers students to a textbook, "Of Pandas and People," for more information.

Nilsen testified as a witness for the defense during the fourth week of a landmark federal trial that could determine whether intelligent design can be discussed in public school biology classes.

Eight families are suing to have intelligent design removed from the curriculum because they believe the policy essentially promotes the Bible's view of creation, and therefore violates the constitutional separation of church and state.

Intelligent design supporters argue that life on Earth was the product of an unidentified intelligent force and that natural selection cannot fully explain the origin of life or the emergence of highly complex life forms.

Nilsen said today he didn't think the district's approach to intelligent design would get as involved as it did. He originally envisioned teachers making only passing references to the concept in biology class.

But when teachers started asking how to implement it, the district developed the statement to be read in class.