Statistical Tests

Statistical Tests

1. Parametric tests are more powerful; data must...

   • Have an interval or ratio level of measurement
   • Be drawn from population with normal distribution
   • Both samples have equal variances

2. Statistical tests produce a calculated value. To determine significance this is compared to a critical value found in a statistical table. Need to know...

   • Significance level (usually p=0.05)
   • One-or two-tailed test (directional and non-directional hypotheses respectively)
   • Value of N or df