Question

Professor lyon decided to study food preferences of u.s. college students, so he asked his students to volunteer to participate in a lengthy survey. professor lyon's survey results are probably invalid because he did not use: an operational definition. random selection. a valid hypothesis. independent and dependent variables.

Answer 1

I believe it’s random selection. Because the students had to volunteer to participate, only those who are passionate about the topic would be included in the data, leading to non response bias. Therefore, there needs to be a more random way to select he students to participate.