STA2023 Quiz 1 Answers

The study of how to collect, organize, analyze, and interpret numerical and categorical information.

A series of steps followed to solve problems including collecting data, formulating a hypothesis, testing the hypothesis, and stating conclusions (choose, perform, develop, design, gather, analyze, formulate)

Numeric values(graphs) calculated from a dataset with the purpose of characterizing the behavior of the variables

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

set of all the individuals of interest in a particular study

A population in which each individual member can be given a number

collection of objects or individuals that are no boundaries or we can not measure about the total number of individuals in the occupied territories

subset of the population. individuals selected from a population, usually intended to represent the population in a research study

value that describes a population

Value that describes a sample

A characteristic about each individual element of a population or sample

value of the variable associated with one element of a population or sample. This value may be a number, or a symbol

the set of values collected for the variable from each of the elements belonging to the sample

a planned activity whose results yeild a set of data

naturally occuring discrepency between a sample statistic and the cooresponding population parameter

the objects described by a set of data: person (animal), place, and thing. In a medicinal trial, the people in the study referred to as called subjects

one that is relevant or appropriate asa representation of that property.

measurement such that the random error is small

In Population data, the variable is measured for EVERY individual of interest

in sample data, the variable is measured from ONLY SOME of the individuals of interest

variable that quantifies an element of the population. has a numerical measurment for which operations such as addition or averaging make sense.
Ex: Ag, GPA, Tuition, Fees

A variable that categorizes or describes an element of a population. has a nominal measurement that descibes an individual by placing them in a category or group.
Ex: Phone number, college year, addresses.

characterized by gaps or interruptions in the values we assume. gaps implies absence between those values. ALl values are whole numbers
Ex: number of cars in garge, count of males in a group

does not possess the gaps or interruptions characteristic of a discrete variable. decismals are allowed between any two values.
Ex: length of pole, height of basketball player, age of tree

an unordered set of categories only by name. only permit you to determine whether two individuals are the same or different

an ordered set of categories. Ordinal measurements tell you the direction of difference between two individuals

ordered series of equal size categories. Identify direction and magnitude of a difference. The zero point is located arbituarily on an interval scale

an interval scale where a value of zero indicates none of the variable. ratio identifies the direction and magnitude of difference and allows ratio comparisons of measurement.

1. Identify the variable(s) of interest (the focus) and the population of the study.
2. Develop a detailed plan for collecting data. If you use a sample, make sure the sample is representative of the population.
3. Collect the data.
4. Describe the data, using descriptive statistics techniques.
5. Interpret the data and make decisions about the population using inferential statistics.
6. Identify any possible errors.

the degree of dispersion (spread) of data points in a distribution

A variable that has an important effect on the response variable and the relationship amoung the variables in a study but is not one of the explanatory variables studied either because it is unknown or not measured.

two variables such that their effects on the respose variable cannot be distingushed from eachother

any specific experimental condition applied to the subjects

a researcher observees and collects data but does not change existing conditions

a researcher applies a treatment to a part of a population and observes the responses to the treatment. another part of the population is given a placebo called the control group

occurs when a subject recieves no treatment, but believes he or she is in fact recieveing treatment and responds favorably

a random process is used to assign each individual to one of the treatments

individuals are first sorted into blocks, and then a random process is used to assign each individual in the block to one of the treatments

an experiment in which the subjects alone do not know which treatment they are recieving

an experiment in which neither the subjects or the people working know which treatment each is recieving

reduced margin of error

numerical facsimile or representation of a real world phenomenon

used to assign individuals to the treatment groups. this helps prevent bias in the selected members for each group. this includes using an appropriate sampling technique

Experiment, survey, census, sampling frame, sample design

no bias introduces by the sampling technique employed. the process by which the sample data is selected progreses without definite aim, reason, or pattern

measurement mistake caused by the factors that vary from one measurement to another; statistical error due to chance

each element of the pop has an equal probability of being selected. a random number table is utilized to select the individual elements of the pop for the sample

assign each element of the population to a group (stratum). perform simple random sampling from each stratum

assign each element of the population a group or cluster. randomly select the desired number of clusters. every element within the selected cluster is used for the sample

list every member of the target population and uniquely assign a number to each member. randomly select a number. this number will be the starting point of the sample selection. Select member for the sample at equivalent intervals.

a statistical method of drawing representative databy selecting people bc of the ease of their volunteering or selecting units because of their availability or easy access

a sampling method where the pop is divided into a number of primary groups from which samples are drawn. these are then divided into secondary groups from which samples are drawn, and so on

a sampling method that produces data which systematically differs from the sampled population. An unbiased sampling method is not biased.

sample collected from those elements of the pop which chose to contribute the needed information on their own initiative

The science of data.

Objects described by a set of data, they do not necessarily have to be people.

A piece of data about the individual.

The entire group of individuals we want information about.

A group in the population.

A number that describes a characteristic of the population

A number that describes a characteristic of the sample.

A characteristic of an individual.

Separates individuals into categories.

Separates individuals based on numeric values.

Tells us possible values for the variable and how often certain variables occur.

Study where researcher observs but does nothing to influence outcome or responses.

Researcher experiments to influence outcomes and responses.

The way to select samples.

When responses are slanted toward certain outcomes.

Respondeds choose to be included in surveys. Ex: Comment cards at hotels.

Researcher samples those who are willing/available.

Not sampling from the entire population.

Those who don’t respond to surveys, equal to the number surveyed minus the number responded, all divided by the number surveyed.

A form of innacurate responses.

How a question is worded: may have some affect on answers.

A random sample that allows every possible sample of size n the same chance of being selected.

Select a starting point at random and then choose every kth individual, where k = (Population Size)/(Sample Size) rounded DOWN to nearest whole number

Divide the population into groups and take a SRS of each group.

Divide the population into groups, but this time take a SRS of groups