Week 1: Introduction to Statistics Flashcards
Statistics is concerned with…
scientific methods for collecting, summarizing, organizing, presenting and analyzing data as well as drawing conclusions and making reasonable decisions based on such analysis.
What is an individual?
The objects being described by the data. Needs clear defintion of what the individual is and how many there are.
What is a variable?
The measurement made on an individual - the characteristics of the individual.
What is a random variable?
A variable whose value may change depending on chance.
What is a variate?
A particular value of a random variable.
What is a population?
The totality of data being referenced.
Two ways of describing a population are…
1) The distribution of its measurements (mean, S.D., etc)
2) The probabilities of the values of a random variable.
Describe how error and uncertainty are different from one another.
Error: experimental error and natural variability.
Uncertainty: sampling & lack of knowledge.
Name two types of scientific investigations, explain them.
1) Exploratory: fact finding, often no hypothesis in mind.
2) Controlled experimentation: begin with specific hypothesis in mind.
Name two subdivisions of controlled experimentation. How are they different?
Observation study and experiments.
Observational study takes measurements of something without control while experiments manipulate individuals and do something to observe a response with a control.
How might one describe empirical probability?
The relative frequency of a event occuring over some number of instances.
Name two types of statistical analysis.
1) Exploratory data analysis.
2) Statistical inference.
What is a sample?
A subset of a population.
Why might it be a good idea to sample?
1) Cost
2) Utility
3) Accessibility
What is statistical inference?
A set of procedures used in making appropriate conclusions about a whole, based on limited number of observations.
