Different factors can play a role in the validity of a test which can pose threats. Ary, Sorensen, and Walker (2014) refer to these factors as construct irrelevant ones. Computer as an outstanding technological feature has changed our daily life. Computer in the educational contexts has affected the way we learn. Every new innovation has its specifications and problems. Computer like other innovations has aspects that should be investigated. In some cases, computer can distort the tests results and be a source of threat for test validity (construct irrelevant variance). Besides computer familiarity, other demographical factors such as gender, age, mother tongue and filed of study can be the sources of construct irrelevant variance. Therefore, the researchers chose to analyze the role of these phenomenon in the assessing procedure. Gender, age, mother tongue, and field of study were those variables that in this survey the researchers wanted to probe their probable relationship with the participants’ TOEFL IBT results. In order to do this, one hundred participants were assigned to two groups-the humanities and engineering-and they answered computer familiarity and attitude toward computer questionnaires and a computer based TOEFL IBT® . At the first step, the level of computer familiarity was investigated and the next stage was related to probing attitude of the participants toward computer and effect of three specified variables (age, gender, and mother tongue) on the test results. Results did not indicate meaningful relation between these variables and test scores. By referring to these results it can be claimed that computers as well as other demographic variables will not have any adverse effect on the test results of TOEFL iBT scores.