Data_Handling_Inferential_Statistics

Question 1

Define nominal, ordinal and interval data

Answer 1

• Nominal: categorical
• Ordinal: Ordered (i.e. 1-10)
• Interval: Numerical (time, weight, temperature, etc)

Question 2

List the types of statistical tests (and mnemonic to remember them by)

Answer 2

• Chi-Squared
• Sign test
• Chi-Squared (repeated in table)
• Mann-Whitney
• Wilcoxon
• Spearman’s rho
• Unrelated t-test
• Related t-test
• Pearson’s r
  (Carrots should come mashed with sweetcorn under roast potatoes)

Question 3

Explain the calculated and critical values in statistical tests

Answer 3

• Test gives calculated value, is compared with critical value
• Depends on type of test, calculated value must be either greater or less than critical value for result to be significant

Question 4

Explain the types of errors in statistical tests

Answer 4

• Type I error: false positive, level of significance too high
• Type II error: false negative, level of significance too low

Question 5

What is the level of significance?

Answer 5

0.05 - 5% chance the result was coincidental.

Question 6

What are the features of the Mann-Whitney test?

Answer 6

• Unrelated design
• Ordinal data
• Significant if calculated value less than critical value

Question 7

What are the features of the Wilcoxon test?

Answer 7

• Related design
• Ordinal data
• Significant is calculated value less than critical value

Question 8

What are the features of the unrelated t-test?

Answer 8

• Unrelated design
• Interval data
• Significant if calculated value greater than critical value

Question 9

What are the features of the related t-test?

Answer 9

• Related design
• Interval data
• Significant if calculated value greater than critical value

Question 10

What are the features of the Spearman’s rho test?

Answer 10

• Correlational
• Ordinal data
• Significant if calculated value greater than critical value

Question 11

What are the features of the Pearson’s r test?

Answer 11

• Correlational
• Interval data
• Significant if calculated value greater than critical value

Question 12

What are the features of the Chi-Squared test?

Answer 12

• Can be unrelated or correlational
• Nominal data
• Significant if calculated value greater than critical value