Sample Size and Power Regular Flashcards

Sample Size

The number of participants needed in a study to ensure effective and reliable results.

Statistical Power

The ability of a statistical test to detect significant differences or associations when they exist.

Confidence Interval (CI)

A statistical range that estimates likely values of a parameter in a population, based on sample data.

Random Error

Random differences between study results and true population values that occur by chance.

Systematic Error (Bias)

A consistent flaw in study design that leads to inaccurate results.

Type 1 Error

Occurs when a study shows a significant result, despite no actual difference in the population.

Type 2 Error

Occurs when a study fails to detect a significant result that is actually present.

Narrow Confidence Interval

Indicates higher certainty about the value of the statistic.

Wide Confidence Interval

Suggests less certainty and occurs when the sample size is small.

Sample Size Estimation

The process of determining the appropriate number of participants for a study.

Power of a Study

The likelihood that a study will detect an effect when there is an effect to be detected.

Effect of Sample Size on CI

Larger sample sizes contribute to narrower confidence intervals.

Implications of Type 1 Error

About 5% of tests may show significant results purely due to chance.

Implications of Type 2 Error

Failure to detect a real difference can lead to incorrect conclusions.

Census

An attempt to gather information about every individual in a population.

Statistical Significance

A determination that results observed in study data are unlikely to have occurred by chance.

Selection Bias

Occurs when participants are selected in a way that skews the results.

Measurement Bias

Inaccuracy in data collection or measurement methods.

Confounding Bias

Occurs when an outside factor influences both the dependent and independent variables.

Expected Characteristics of the Sample Population

Assumptions made about the traits of participants in a study prior to analysis.

Resources Optimization

Efficient use of time and funding in the context of participant recruitment.

Extremes in Data Samples

Values that significantly deviate from the average, potentially skewing results.

Statistical Software

Programs used to perform data analysis and calculations for studies.

Precision in Research

The consistency and reliability of study results.

Recruitment Strategies

Methods used to attract participants to a research study.

Statistical Estimations

Calculations made to predict population parameters based on sample data.

Cohort Study

A study design that follows a group of individuals over time to determine outcomes.

Cross-Sectional Study

A study analyzing data from a population at a single point in time.

Experimental Study

A study design in which one or more variables are manipulated to observe effects.

Sensitivity Analysis

An assessment of how variable results may be based on changes in initial assumptions.

Case-Control Study

A study comparing individuals with a condition to those without it to identify risk factors.

Statistical Tests

Procedures used to determine validity of hypotheses based on sample data.

Population Mean

The average value of a characteristic in a whole population.

Sample Mean

The average value of a characteristic in the selected sample.

N (Population)

The total number of individuals in a specified population.

n (Sample)

The number of individuals selected for a study from the population.

Research Design

The structured plan for a scientific study.

Random Sampling

A sampling method where every individual has an equal chance of being selected.

Estimation of Confidence Level

A way to quantify uncertainty regarding sample statistics.

Statistics

The branch of mathematics dealing with data collection, analysis, interpretation, and presentation.

Outcome Measurement

The process of assessing the results associated with a chosen intervention.

Clinical Trials

Research studies involving human participants to evaluate medical interventions.

Power Analysis

A method for determining the necessary sample size for a study.

Bias Minimization

Strategies aimed at reducing systematic errors in a study.

Statistical Association

A relationship between two variables observed in study data.

Informed Consent

Participants' agreement to join a study after being fully informed of its risks and benefits.

Data Collection Methods

Techniques used to gather information from participants in a study.

Statistical Interpretation

The process of making sense of numerical data and drawing conclusions.