A researcher is studying the effect of a new teaching method on student performance. She collects test scores from two groups of students: one group that used the new method and another that used the traditional method. The test scores for the new method group have a mean of 85 with a standard deviation of 10, while the traditional method group has a mean of 78 with a standard deviation of 12. To determine if the new teaching method significantly improves student performance, she conducts a two-sample t-test. If the researcher sets her significance level at $\\alpha = 0.05$, what is the critical t-value she should use for this test, assuming both groups have 30 students?