Chapter 9 (Examining populations and samples in research)

Intraproject sampling

The additional sampling that is done during data collection and analysis to promote the development of quality study findings.

Elements

The individual units of the population and sample are referred to as this.

Acceptance rate

The percentage of subjects meeting sampling criteria consenting to participate in a study.

Refusal rate

The percentage of subjects who declined to participate in the study and the subjects reason for not participating.

What does sampling involve?

This involves selecting a group of people, events, objects, or other elements with which to conduct a study. A sampling method or plan defines the selection process.

nonprobability sampling

This is commonly used in nursing studies because of the limited number of patients available for research.

What does representativeness mean?

This means that the sample, accessible population and target population are alike in as many ways as possible.

Exclusion sampling criteria

Those characteristics that can cause a person or element to be excluded from the target population.

Why was sampling theory developed?

To determine the most effective way to acquiring a sample that accurately reflects the population under study.

Why is a sampling plan created in quantitative research?

To increase representativeness of the target population and decrease systematic bias and sampling error.

Why is a sampling plan created in qualitative research?

To increase representativness of the findings related to the phenomenon, process, or cultural elements being studied.

What factors should we consider when making a decision about sample size ?

Type of study, number of variables, sensitivity of measurement methods, data analysis techniques and expected effect size.

Theoretical sampling

Used in qualitative research to develop a selected theory through research process. This type is used most frequently with grounded theory research, because the focus of this type of research is there development.

Stratified random sampling

Used in situations in which researcher knows some of the variables in the population that are critical for achieving representativness. Variable commonly used for strafrication include age, gender, race, and ethnicity.

Systematic sampling

Used when an ordered list of all members of the population is available.

Quota sampling

Uses a convenience sampling technique with an added feature- a strategy to ensure the inclusion of subject types likely to be underrepresented in the convenience sample.

When is the number of participants in a qualitative study adequate?

When saturation and verification of data are achieved in the study area.

When does verification of the study of data occur?

When the researchers are able to confirm hunches, relationship or theoretical models further.

Sample size

number of subjects participating in the study.

What sampling are used in qualitative research?

purposive, network and theoretical sampling

Where is quota sampling used more frequently?

quantitative and outcome research

What do quantitative and outcome researchers refer to the people as?

subjects or participants

What are important factors to consider in determining sample size for qualitative studies ?

1) scope of study 2) nature of the topic 3) quality of the data collected 4) design of the study

Highly controlled setting

An artificially constructed environment developed for the sole purpose of conducting research.

Partially controlled setting

An environment that is manipulated or modified in some way by the researcher.

Inclusion sampling criteria

Are the characteristics that the subject or element must possess to be part of the target population.

What are the five non probability sampling methods?

Convenience sampling, quota sampling, purposeful or purposive sampling, network sampling and theoretical sampling.

What about probability sampling?

Each person or element in a population has an opportunity to be selected for a sample, which is achieved through random sampling .

Target population

Entire set of individuals or elements who meet the sampling criteria.

Random variation

Expected difference in values that occurs when different subjects from the same sample are examined.

Sampling or eligibility criteria

Includes the list of characteristics essential for eligibility or membership in the target population.

natural or field setting

Is an uncontrolled, real life situation or environment. Conducting a study in a natural setting means the researcher does not manipulate or change the environment for the study.

Power

Is the ability of the study to detect differences or relationships that actually exist in the population.

Simple random sampling

Is the most basic of the probability sampling plans. It is achieved by randomly selecting elements from the sampling frame.

Population

Is the particular group of individuals or elements, such as people with type 2 diabetes, who are the focus of the research.

Research setting

Is the site or location used to conduct a study

Sample retention

Number of subjects who remain in and complete the study.

Sampling methods or plans

Outlines strategies used to obtain samples for studies. Like a design, a sampling plan is not specific to a study.

What do qualitative researchers refer to the individuals as?

Participants

When an elements are person what are they referred to as?

Participants or subjects

What is included in a sampling theory concept?

Population, sampling criteria, target population, accessible population, study elements, reprensentativness, randomization, sampling frame, and sampling method or plan

Accessible population

Portion of the target population to which the researcher has reasonable access.

What is an effective way to determine an adequate sample size for quantitative and outcome studies?

Power analysis

What are the two main types of sampling plans?

Probability and non probability

When is convenience sampling used frequently ?

Quantitative, qualitative and outcome studies

Cluster sampling

Researcher develops a sampling frame that includes a lists of all the states, cities, institutions, or organizations with which element of the identified population can be linked.

What are the common probability sampling methods used in nursing research?

Simple random sampling, stratified random sampling, cluster sampling, and systematic sampling.

Network sampling

Sometimes referred to as "snowball" "chain" or "nominated sampling holds promise for locating participants who would be difficult or impossible to obtain in otherwise or who have not been previously identified for study.

Saturation

Study data occurs when additional sampling provides no new information, only redundancy of previous collected data.

Systematic variation

Systematic bias-a serious concern in sampling- is a consequence of selecting subjects who measurement values differ in some specific way from those of the population.