Comparing Means 2:

• What are the types of t-tests mentioned in the study material?

  Paired samples t-test and one sample t-test
• What software is mentioned for performing t-tests?

  SPSS
• In what format should results be reported?

  APA format
• What does a t-test allow us to do?

  • Compare means for statistical significance
  • Assess differences between sample means
  • Determine if observed differences are due to chance
• What happens each time a sample is taken from a population?

  A different mean will be obtained
• What does a t-test calculate?

  A t-statistic, degrees of freedom, and p-value

  
• What is the t-statistic?

  The difference between means, in standard errors
• What are degrees of freedom?

  The amount of numbers which we are free to estimate
• What does the p-value represent in a t-test?

  The probability of finding the t-statistic if there was no difference in the population
• What is a paired-samples t-test used for?

  • Used for within subjects design
  • All participants exposed to all variables
  • Measures people at two different times to compare means
• Why is the paired-samples t-test considered more powerful than the independent sample t-test?

  It is more likely to find a true effect and has less error
• Why does the paired-samples t-test have less error?

  Because we’re measuring the same people
• What is the first assumption of the paired-samples t-test?

  Interval/ratio data
• What is the second assumption of the paired-samples t-test?

  Random sample from the population
• What is the third assumption of the paired-samples t-test?

  Difference between scores is normally distributed
• What can t-tests determine?

  • Significant difference between two means
  • Independent samples t-test for between-subjects design
  • Paired samples t-test for within-subjects design
• What can a one sample t-test determine?

  Whether a mean is significantly different from a given value
• What is the common process for all t-tests?

  • Calculate the t-statistic: size of the effect in standard errors
  • Calculate degrees of freedom (usually df = n - 1)
  • Calculate p-value: probability of seeing the effect in the sample if there was no effect in the population
  • Consistent reporting across different types of t-tests
• What is the formula for degrees of freedom in t-tests?

  Usually df = n - 1
• What does the p-value indicate in the context of t-tests?

  The probability of seeing the effect in the sample if there was no effect in the population
• How is reporting consistent across different types of t-tests?

  Reporting follows the same format regardless of the t-test type