Exam 1 Stat

Statistics

The science of collecting, analyzing, interpreting, presenting, and organizing data.

Parameters

Numerical characteristics of populations.

Population proportion (p)

The true proportion of a characteristic in a population.

Sample proportion (𝑝̂)

An estimate of the population proportion, calculated from a sample.

Formula for sample proportion

$\bar{p} = \frac{x}{n}$, where x is the number of successes and n is the sample size.

N vs n

N represents the total population size, while n signifies the sample size.

Effect of N = n

When N equals n, the entire population is sampled, leading to no sampling variability.

Sampling variability

The natural variation that occurs in sample statistics due to different samples.

Unbiased sample statistic

A sample statistic that is centered around the true population parameter.

Bias in estimation

A systematic error that leads to a skewed estimation of the population parameter.

Variability in estimation

The degree to which a sample statistic varies from sample to sample.

Margin of error (MOE)

An expression of the amount of random sampling error in a survey's results.

Point estimate

A single value estimate of a population parameter.

Confidence statements

Statements indicating the reliability and uncertainty of an estimate.

Response rate

The proportion of the sample that completes the survey.

Nonresponse rate

The proportion of the sample that does not respond to the survey.

Sampling errors

Errors that result from using a sample to estimate information about a population.

Nonsampling errors

Errors that occur due to nonresponse, misleading questions, or false responses.

Response error

Mistakes made by the respondents, either accidental or purposeful.

Randomized-response technique

A method used to improve the accuracy of responses to sensitive questions.

Stratified random sampling

A sampling method where the population is divided into strata (subgroups), and random samples are taken from each.

Clustered random sampling

A sampling method where entire clusters are sampled randomly instead of individuals.

Systematic random sampling

A sampling method where every individual is selected from a pre-determined list.

Statistical significance

The likelihood that a result or relationship is caused by something other than mere random chance.

Randomized comparative experiment

An experiment that randomly assigns subjects to different treatment groups to compare outcomes.

Confounding effects

When the effect of one variable on another is mixed up with the effect of a third variable.

Confounding Effect

When effect on the response variable can’t be distinguished.

Treatment group

The group of subjects that receive the treatment being tested in an experiment.

Control group

The group of subjects that do not receive the treatment or receive a placebo.

Placebo effect

A beneficial effect in a patient resulting from the mere expectation of treatment.

Hawthorne effect

A change in behavior that results from being observed or knowing one is part of an experiment.

Blinding in studies

A technique used to prevent bias in research by keeping participants unaware of whether they are receiving treatment or placebo.

Clinical trials

Research studies that test how well new medical approaches work in people.

Equipoise

A state of uncertainty about whether a treatment is beneficial.

Data Safety Monitoring Boards (DSMBs)

Groups of people responsible for monitoring patient safety and treatment effectiveness during a clinical trial.

IRBs (Institutional Review Boards)

Committees that review and approve research involving human subjects to ensure ethical standards are met.

Informed consent

The process of obtaining voluntary agreement from participants after providing them with adequate information.

Confidentiality

The ethical principle that data and personal information of study participants should be kept private.

Anonymity

A practice where the identity of the participants is unknown even to the researchers.

Tuskegee syphilis experiment

A notorious clinical study conducted in the US where treatment was withheld from African American men with syphilis without their informed consent.

What is a Lurking Variable?

Variable that has an important effect on the relationship among the variables in a study but is not one of the explanatory variables studied.

Non-adherence

Subjects don’t follow the set dosage amount in dosage frequency

What is Retrospective Study

A type of observational study that asks subjects to recall, no treatment exposed.