Title: Chapter 1 Statistics: The Art and Science of Learning from Data
1Chapter 1Statistics The Art and Science of
Learning from Data
- Learn .
- What Statistics Is
- Why Statistics Is Important
-
2Chapter 1
- Learn
- How Data is Collected
- How Data is Used to Make
- Predictions
3Section 1.1
- How Can You Investigate using Data?
4Health Study
- Does a low-carbohydrate diet result in
significant weight loss?
5Market Analysis
- Are people more likely to stop at a Starbucks if
theyve seen a recent TV advertisement for their
coffee?
6Heart Health
- Does regular aspirin intake reduce deaths from
heart attacks?
7Cancer Research
- Are smokers more likely than non-smokers to
develop lung cancer?
8To search for answers to these questions, we
- Design experiments
- Conduct surveys
- Gather data
9Statistics is the art and science of
- Designing studies
- Analyzing data
- Translating data into knowledge and understanding
of the world
10Example from the National Opinion Center at the
University of Chicago
- General Social Survey (GSS) provides data about
the American public - Survey of about 2000 adult Americans
11Example from GSS Do you believe in life after
death?
12Three Main Aspects of Statistics
- Design
- Description
- Inference
13Design
- How to conduct the experiment
- How to select the people for the survey
14Description
- Summarize the raw data
- Present the data in a useful format
15 Inference
- Make decisions or predictions based on the data.
16Example from GSS On a typical day, about how
many hours do you personally watch television?
17What percentage of the people surveyed reported
watching 0 hours of TV a day?
18Example Harvard Medical School study of Aspirin
and Heart attacks
- Study participants were divided into two groups
- Group 1 assigned to take aspirin
- Group 2 assigned to take a placebo
19Example Harvard Medical School study of Aspirin
and Heart attacks
- Results the percentage of each group that had
heart attacks during the study - 0.9 for those taking aspirin
- 1.7 for those taking placebo
20Example Harvard Medical School study of Aspirin
and Heart attacks
Example Harvard Medical School study of Aspirin
and Heart attacks
- Can you conclude that it is beneficial for
people to take aspiring regularly?
21Section 1.2
- We Learn About Populations Using Samples
22Subjects
- The entities that we measure in a study
- Subjects could be individuals, schools,
countries, days,
23Population and Sample
- Population All subjects of interest
- Sample Subset of the population for whom we have
data
24Example Format
- Picture the Scenario
- Question to Explore
- Think it Through
- Insight
- Practice the concept
25Example The Sample and the Population for an
Exit Poll
- In California in 2003, a special election was
held to consider whether Governor Gray Davis
should be recalled from office. - An exit poll sampled 3160 of the 8 million people
who voted.
26 Example The Sample and the Population for an
Exit Poll
Example The Sample and the Population for an
Exit Poll
- Whats the sample and the population for this
exit poll? - The population was the 8 million people who voted
in the election. - The sample was the 3160 voters who were
interviewed in the exit poll.
27Descriptive Statistics
- Methods for summarizing data
- Summaries usually consist of graphs and numerical
summaries of the data
28Types of U.S. Households
29Inference
- Methods of making decisions or predictions about
a populations based on sample information.
30Parameter and Statistic
- A parameter is a numerical summary of the
population - A statistic is a numerical summary of a sample
taken from the population
31Randomness
- Simple Random Sampling each subject in the
population has the same chance of being included
in that sample - Randomness is crucial to experimentation
32Variability
- Measurements vary from person to person
- Measurements vary from sample to sample
33Inferential Statistics are used
- To describe whether a sample has more females or
males. - To reduce a data file to easily understood
summaries. - To make predictions about populations using
sample data. - To predict the sample data we will get when we
know the population.