1. What is most important to determine when understanding missing data? 
  2. What are the advantages and disadvantages of common missing data methods? 
  3. When might one use as a threshold or guideline in terms of when missing data be estimated vs.

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Osborne & Overbay (2004). The power of outliers (and why researchers should ALWAYS check for them. Practical Assessment, Research & Evaluation, 9 (6), 1-8.