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StatsToDo : Sample Size for Estimating Cronbach's Alpha

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Explanations Javascript Program R Codes
Data
Sample Size : Data input a table of 5 columns
  - Each row contains data from a separate study
  - Col 1 = Probability of Type I Error α
  - Col 2 = Power (1 - β)
  - Col 3 = number of items in the group (questions in a factor)
  - Col 4 = Cronbach Alpha required or anticipated
  - Col 5 = Reference or hypothetical Cronbach Alpha, usually 0 for null hypothesis
  

Power : Data input a table of 5 columns
  - Each row contains data from a separate study
  - Col 1 = Probability of Type I Error α
  - Col 2 = Sample size used
  - Col 3 = number of items in the group (questions in a factor)
  - Col 4 = Cronbach Alpha found
  - Col 5 = Reference or hypothetical Cronbach Alpha, usually 0 for null hypothesis
  

Confidence Interval : Data input a table of 4 columns
  - Each row contains data from a separate study
  - Col 1 = Percent confidence (usually 95 or 99)
  - Col 2 = Sample size used
  - Col 3 = number of items in the group (questions in a factor)
  - Col 4 = Cronbach Alpha found
  

Pilot Study : Data is for a single plan, a single column with 5 rows
  - Row 1 : Percent confidence required, usually 95 or 99
  - Row 2 : Number of items in the data
  - Row 3 : Cronbach's Alpha to be detected
  - Row 4 : Sample size interval for tabulation of changing width of the confidence interval.
      This is usually established by trial and error, starting at about 5
  - Row 5 : Maximum sample size or tabulation of changing width of the confidence interval.
      This is usually established by trial and error. For most clinical studies however,
      the sample size is between 10 and 200, and this range can be used as starting levels