What is statistics?
collection, organization, analysis, interpretation, and presentation of data
Claude’s answer
Some Questions
Here are some questions we can answer using statistics:
- Are some airlines more likely to have delayed flights than others?
- Over the last five years, what is the average time to complete a degree for Montclair State undergrads?
- Does a new drug reduce the number of deaths in patients with severe heart disease?
Types of Questions
- descriptive
- comparative
- relationship-based
Match each question in the previous slide with a question type
Descriptive Research Questions
Examples of how to start your descriptive question:
- How many?
- How often?
- How frequently?
- How much?
- What percentage?
- What proportion?
Comparative research questions
- What are the differences?
Relationship-based questions?
- What is the relationship between …?
- What is the effect of … on …?
Comparison
Go to the Bureau of Transportation Statistics website and try to answer the following question:
Which of the 4 largest airlines in the US (American, Delta, Southwest, United) has the best On-Time Arrival Performance between January and September 2024?
Descriptive/Summary statistics
- American: 69.77%
- Southwest: 76.78%
- United: 76.87%
- Delta: 80.36%
Can these summary statistics help you make decisions about which airline to fly?
Inferential Statistics
Are the differences across groups “real”?
Probability
- If you flip a coin 100 times, how many times will the coin land heads?
- Suppose it lands 51 heads – can we conclude that the coin is not fair?
Observed differences may be real – or they may be a result of chance (natural variation)
We use statistics to determine if differences are large enough that we can reject the hypothesis that they are due to chance