The ICR defined its work in terms of three ministries: research, writing and speaking. Historian of science Ronald L. Numbers states that "its name, the institute for years conducted little research outside the confines of its modest library" and cites (founding member) Duane Gish as "explain[ing apologetically in 1978, the staff devoted much of its research effort to scouring the scientific literature for references favorable to creationism." Numbers does note that it engaged in a number of archaeological and geological expeditions, including two in search of the mythical Noah's Ark, with geologist Steven A. Austin, working as an "off and on" visiting scientist until taking a full staff position in 1979, single-handedly conducting most of its non-literary research. Influential scientific creationist Walter E. Lammerts complained that "[the main trouble is that Henry looks at this whole thing as a sort of 'missionary' effort rather than a scientific one." It maintained tax-exempt status as a religious institution carrying out "non-scientific research."