A psychological researcher designs a study to determine whether positive feedback affects student test performance. The researcher asks each student enrolled in AP Psychology to participate. Students are divided into 3 groups—positive feedback, negative feedback, and no feedback. After completing the Module 1 FRQ, students in Group 1 are provided with positive feedback about their work and encouraged to keep working hard. Students in Group 2 are given criticisms of their writing and encouraged to rethink taking the course. Students in Group 3 are only given a numeric score, no written feedback. After reading the feedback, participants complete a survey measuring self-esteem and take their Module 1 Exam. Test scores are compared for the three groups. Following the test, the participants in Group 1 that received positive feedback, are debriefed and the true nature of the research explained. Results of the study indicate that participants who received positive feedback on their FRQs scored on average of 8 points higher than students who received negative feedback or no feedback at all. Which of the following violations to ethical guidelines is committed in the study described?

Confidentiality
Exposure to harmful procedures
Failure to debrief all participants
Inappropriate use of deception
Voluntary participation