# AP Statistics 1

## 28 terms · First Semester final terms

### Individuals

The people or objects involved in the study

### Variable

The characteristic of the individual to be measured or observed

### Quantitative variable

A variable that has a value or numerical measurement for which operations such as addition or averaging makes sense

### Qualitative variable

A variable that describes an individual by placing the individual into a category or group such as male or femle

### Population data

In ___ the variable is from every individual or interest

### Sample data

In ___ the variable is from only some of the individuals or interest

### Nominal

data that consist of names, labels, or categories

### Ordinal

differences between data values either cannot be determined or are meaningless

### Interval

differences between data values are meaningless

### Ratio

both differences between data values and ratios of data values are meaningless. Data at the ratio level have a true zero

### Descriptive statistics

methods of organizing, picturing, and summarizing information from samples or populations

### Inferential statistics

methods of using information from a sample to draw conclusions regarding the population

### Simple random sample

every sample of size n from the population has an equal chance of being selected and every member of the population has an equal chance of being included in the sample

### Simulation

numerical facsimile or representation of a real-world phenomenon

### stratified sampling

technique in which the entire population is divided into distinct subgroups or strata, based on a specific characteristic: age, income, education level, etc. Random samples are drawn from each stratum

### Systematic sampling

technique in which members of the population are sequentially numbered. Then, from starting point, every kth member of the population is included in the sample

### Cluster sampling

technique in which the entire population is divided into pre-existing segments or ___. The ___ are often geographic. They are randomly selected and every member of each selected ___ is included in the sample

### Convenience sampling

technique in which data are used from population members that are readily available

### Census

measurements or observations from the entire population are used

### Sample

measurements or observations from a representative part of the population should be used

### Observational study

observations and measurements of individuals are conducted in a way that doesn't change the response or the variable being measured

### Experiment

a treatment is deliberately imposed on the individuals in order to observe a possible change in the response or variable being measured

### Placebo effect

occurs when a subject receives no treatment, but incorrectly believes he or she is in fact receiving treatment and responds favorably

### Control group

"dummy treatment" enabling researchers to control for the placebo effect.

### Confounding variables

Control group is used to account for the influence of other known or unknown variables that might be an underlying cause of a change in response in the experimental group

### Randomization

used to assign individuals to the two treatment groups. This helps prevent bias in selecting members for each group

### Double-blind

Neither individuals in study nor observers know which subjects are receiving the treatment

### Bias

favoring of or against one thing, person, or group compared with another, usually in a way considered to be unfair.