Week 5: Sampling Methods & Generating Reserch Ideas

Cluster Sampling

Probability sampling using a group or unit rather than an individual.

Convenience Sampling

A form of nonprobability sampling that consists of collecting data from the group that is available.

Exclusion Criteria

The list of characteristics that would eliminate a subject from being eligible to participate in a study.

Inclusion Criteria

The list of characteristics a subject must have to be eligible to participate in a study.

Nonprobability Sampleing

Methods in which subjects do not have the same chance of being selected for participation (not randomized).

Probability Sampling

Techniques in which the probability of selecting each subject is known (randomized).

Quote Sampling

A form of nonprobability sampling in which you select the proportions of the sample for different subgroups, much the same as in stratified sampling but without random selection.

Sampling Bias

A systematic error made in the sample selection that results in a nonrandom sample.

Sampling Distribution

All the possible values of a statistic from all the possible samples of a given population.

Sampling errors

Differences between the sample and the population that occur as a result of randomization or chance.

Sampling method

The process employed to select the subjects for a sample from the population being studied.

Sampling random sampling

Probability sampling in which every subject in a population has the same chance of being selected.

Stratified Sampling

Probability sampling divides the population into subsamples according to a characteristic of interest and randomly selects the sample from these subgroups.

Systemic Sampling

Probability sampling involving the selection of subjects according to a standardized rule.

Alpha (α)

The significance level, usually 0.05. The probability of incorrectly rejecting the null hypothesis or making a type I error.

Alternative Hypothesis

Usually, the relationship or association or difference that the researcher actually believes to be present.

Clinically significant

A result that is statistically significant and clinically useful.

Fail to reject the null hypothesis

Not having enough statistical strength to show a difference or an association.

Hypothesis

An observation or idea that can be tested.

Hypothesis Testing

The application of a statistical test to determine whether an observation or idea is to be refuted or accepted.

Null Hypothesis

No difference or association between variables that is any greater or less than would be expected by chance.

Reject the null hupothesis

Having enough statistical strength to show a difference or an association.

Statistical Significance

The difference observed between two samples is large enough to conclude that it is not simply due to chance.

Type I error

Incorrectly rejecting the null hypothesis.