Statistical Questions

1
Statistical Questions
2
Scale Questions

• Name the scale type
• Fahrenheit
• Latency
• Ethnicity
• Speed
• What is the difference between a subjective and
  objective measure?

3
Scale Questions

• Training experts developed a new program to train
  people how to ship products using an express
  delivery company. Randomly assigned participants
  received either the traditional or new
  training. Using a test at the end of training
  the company found
• Old training 25 New training 76
• The experts concluded that the new training was
  more than twice as good. Legitimate?

4

• The UI football team has had a losing season.
  When the coached averaged the jersey number of
  the UI team and compared it to the same average
  for the opposing team, he found that the UI team
  had significantly lower jersey numbers, p lt .01.
  Is this a legitimate use of statistics?

5
Research Methods

• When conducting a statistical test, which
  research hypothesis is tested?

6
Research Methods

• After rejecting the null hypothesis, a researcher
  concluded that the data supported her alternative
  hypothesis. How is this possible if she didnt
  test it?

7
Interpretation

• True or false
• The probability of a Type I error is alpha.
• p the probability that a result occurred by
  chance.
• With p .01, a researcher can be confident that
  the findings can be easily replicated.

8

• True or False
• With p .0001, there is very little chance the
  null hypothesis is true.
• A student collected two samples of 70 subjects.
  The means of the two samples were 45.2 and 48.3,
  respectively. The student collected an
  additional 30 observations per group. The new
  means should be the same.

9
Statistics

• True or False
• One can use r and t for the same analyses.

10
Calculations

• What is the approximate standard deviation of a
  normal distribution that ranges from 37 to 178?
• Is it possible to analyze continuous data such as
  GRE scores using a categorical technique such as
  chi-square?

11
Calculations

• A new instructor wanted to increase the
  performance of students in her class. The
  average on the last test was 55 (S 5.64). She
  added 10 to each test score. Estimate the new
  standard deviation.