Introduction to data analysis: Case
studies with iSIKHNAS data
Day 3
Beef self-sufficiency
Introduction to case study 3:
Beef self-sufficiency
• Scenario
• Question of interest
• Limitations to conclusions (deficient datatime frame short)
Key concepts for hypothesis testing (1)
• Objective and question of interest
Key concepts for hypothesis testing (2)
• Null and alternate hypotheses
Key concepts for hypothesis testing (3)
• Determine an appropriate statistical test
• Watch additional PowerPoint on which test to
use.
Key concepts for hypothesis testing (4)
• Calculate a test statistic value
Key concepts for hypothesis testing (5)
• Determine the region of test statistic values
where you will reject or retain the null
hypothesis
Key concepts for hypothesis testing (6)
• Determine a probability of observing the test
statistic if the null hypothesis is true
Key concepts for hypothesis testing (7)
• Reject or retain the null hypothesis
Key concepts for hypothesis testing (8)
• Make inferences about the population of
interest i.e. answer your question of interest.
Case study 3: Objective
• Exercise 15
Case study 3: Data management
• Exercise 16
Case study 3: Description of data
• Exercise 17
Case study 3: Hypothesis testing
• Exercise 18
• Exercise 19
Summary of case study 3
Conclusions from course
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Importance of data analysis
iSIKHNAS data now available
Steps in data analysis
Consolidate your skills
Advance your skills
– Software (e.g. R)
– Text books (e.g. R and statistics)
• Extension work with R in Appendix 1
The end of day 3