When Alice administered a questionnaire to a group of primary school children, she was very surprised by their levels of awareness regarding student violence. Many of the questions were undiluted...

When Alice administered a questionnaire to a group of primary school children, she was very surprised by their levels of awareness regarding student violence. Many of the questions were undiluted descriptions of violent incidents. On observing the video recording of the interviews, the principal pointed out how she had almost ­always accompanied the correct answer with a sympathetic smile. On seeing her smile, the children immediately chose that answer, which seemingly affected the conclusion of the research. Which threat to construct validity is evident here?

a.            Participant reactivity to the nature of the topic

b.            Experimenter effect influencing the participants

c.             Positive self-presentation, as more aware of the topic

d.            Participant anxiety to the questioning about violence

e.            Irrelevancy of the topic to the sample