In the original, unaired pilot of The Big Bang Theory, the conception of the female lead was very different. She was called Katie, and was envisioned as "a street-hardened, tough-as-nails woman with a vulnerable interior". Sheldon and Leonard would "approach her with honesty, to draw the real, sensitive Katie out". The role was played by Amanda Walsh. However, the test audiences reacted to the character negatively, seeing her as too mean. Because of this, the character was changed, and the role was recast. Marisa Tomei, Tara Reid, Elizabeth Berkley, and Jodi Lyn O'Keefe were all also considered for the role.
