The 2017 online data set seemed to demonstrate that people knew more languages than the 2016 index card set. This may be directly related to the ability of people to have time to think and list the additional languages they were familiar with.The setting, the timing, and the ability to enter more languages (there may have been less room to fill in these details on index cards) could have impacted these results, enabling people to realize that they were familiar with more languages than they might have initially thought. The presence of an interviewer while filling out the questionnaire may also have affected the results, as some might have been influenced to fill out more languages (possibly to please the interviewer) or have the ability to ask questions of the interviewer (and therefore enter more languages).
In addition, the way in which people were referred to the questionnaire may also have affected the results. For example, if people were referred to the study, there may have been a bias of including those (such as those interested in linguistic anthropology) who had interests in languages, those who already knew a lot of languages, or those who were being exposed to the languages, perhaps from their peers/friend groups. In addition, the particular mix of students being admitted to Seton Hall each year (perhaps some years were more diverse), may also have been reflected in the 2017 online data.