Which of the following statements regarding statistical significance is true?
1) A statistically significant difference can occur between experimental groups and control groups even if the magnitude of difference between groups is quite small.
2) If a statistically significant difference between groups occurs, it means that a large and important change occurs in at least one of the groups.
3) Statistically significant findings in a clinical research study suggest that the treatment is successful and highly recommended.
4) The terms "statistically significant" and "clinically significant" are interchangeable.