TERMS

• Hypothesis Testing


  A statement or assumption about the characteristics of one or more populations
• One-tailed 


  This test can be either left-tailed or right-tailed
• Researcher rejects the true null hypothesis

  Type I error occurs
• Power of a test


  The probability of rejecting the null hypothesis when it is false
• Alternative hypothesis


  An opposing statement to the null hypothesis
• Significance level


  A measure of the strength of the evidence that must be present in your sample before rejecting the null
• Degrees of freedom


  Calculated by subtracting one from the number of items within the data sample
• Critical value


  This value is compared with the obtained test statistic to determine whether the null hypothesis has to be rejected or not
• Failing to reject the false null hypothesis

  Type II error
• Test statistic


  A number, calculated from a statistical test, used to find if your data could have occurred under the null hypothesis
• Confidence level


  The probability with which the estimation of the location of a statistical parameter in a sample survey is also true for the population
• Null hypothesis


  It infers no significant difference, effect, or relationship between variables in the population being studied
• Rejection region


  A set of values for the test statistic for which the null hypothesis is rejected
• Conclusion


  The final decision of the hypothesis test
• Decision


  A statement based upon the null hypothesis. It is either "reject the null hypothesis" or "fail to reject the null hypothesis"