Statistics Chapter One Terminology
Terms
undefined, object
copy deck
- Sampling with replacement
- A number is not removed from the population because it has occured
- Stratified Sampling
- Classes or strata are formed inside a population. A simplee random sample is than drawn from each class or strata
- Systematic sampling
- Every nth element of a population is chosen (like every 12th person)
- Cluster sampling
- Populations are divided into areas. Areas are than selected at random and every element of the area is tested
- Convenience Sampling
- Elements chosen by how handy they happen to be
- Census
- Count everyone or everything
- Survey
- Ask a sample to gather data
- Problems with surveys
- the sample may be biased, self-selected, or may contain a hidden bias, which is unknown to the surveyor and even the population. you may miss variables when asking your question
- Statistics
- Involves the organization of data so as to make sense of the data and possibly predict the future using the data.
- Qualitative Data
- Data can be separated into different categories that are distinguished by some nonnumerical characteristics
- Quantative Data
- The data consist of numbers representing counts or measurments
- Measurement
- Somewhat arbitrary assignment of a number to an event or item
- Discrete Measurements
- The data can only have finite number values
- Continuous measurement
- Infinitely many possiblities for values
- Population
- The whole set or group
- Sample
- A subset of the population
- Experiment
- Set up a control group, an experimental, treat the experimental group and measure what happens.
- Simulation
- run a numerical model of the situation, probably on a computer, but not necessarily. (monopoly)
- Simple random Sample
- Everything or everybody in the population has an equal chance of being chosen
- Observational Study
- Observe and measure individuals in a way that doesn't change the response or the variable being measured
- Placebo
- No treatment or a dummy treatment
- Randomized
- Two-treatment experiment: Experiment and control group
- Lurking variables
- Unknown or hidden effects
- Bias
- Slanting of the data one way or another
- Hidden bias
- Unknown slanting of hte data one way or another
- Replication
- If the experiment is repeated, do you obtain the sam result? or are the results due to chance alone
- Generalizing results
- The results for a particular population used for the experiment may not apply to other populations.
- Histograms
- Varies from a normal bar graph by the bars always touching and hte width of hte bar represents a quantative value. Need a frequency table
- Lower class limit
- The smallest number that belongs in a different class
- Upper class limit
- The largest numbers that belong in the different classes
- Class bounddaries
- half way between two limits
- Class marks
- The midpoint of each class
- Class width
- the difference betwen 2 consecutive lower class limits or boundaries