SNHP 330: Research and Evidence-Based Practice - Week 11

Vocabulary practice flashcards covering sampling methods, statistical power, survey development, data management, and descriptive statistics from Week 11 of SNHP 330: Research and Evidence-Based Practice.

Target Population

The larger group about which a researcher aims to draw conclusions.

Source Population

The accessible subset of the target population from which participants can be sampled.

Sample/Study Population

The subset of the population that is actually included in the study.

Simple Random Sampling

A probability sampling method where every member of the population has an equal chance of selection.

Stratified Sampling

A probability sampling method where the population is divided into subgroups and samples are drawn from each.

Cluster Sampling

A probability sampling method that involves randomly selecting predefined groups (e.g., schools, clinics).

Convenience Sampling

A non-probability sampling method where participants are chosen based on being the easiest to reach.

Purposive Sampling

A non-probability sampling method that selects specific individuals to obtain unique insights.

Quota Sampling

A non-probability sampling method where recruitment continues until specific category quotas are filled.

Snowball Sampling

A non-probability sampling technique where existing study participants recruit additional participants.

Sampling Bias

A systematic error resulting from non-random selection of study participants.

Non-Response Bias

An error that occurs when there are systematic differences between respondents and nonrespondents.

Sampling Error

Natural variation that occurs by chance in a sample; it is reduced by increasing sample size rather than altering bias.

Statistical Power

The probability of finding a difference when one truly exists, or correctly rejecting a false null hypothesis ($1 - \beta$); typically set at $80\%$ ($0.80$) in health research.

Effect Size

A metric describing the magnitude of a difference or association between groups or variables, independent of sample size.

Statistical Significance Level

The threshold (typically $0.05$) for declaring a result statistically significant, which also defines the acceptable risk of a false positive (Type I error).

Questionnaire (Survey Instrument)

A standardized tool used to systematically gather data from study participants.

Closed-Ended Questions

Questions that provide predefined response options (such as Yes/No or Likert scales).

Open-Ended Questions

Questions allowing respondents to formulate answers in their own words.

Likert Scale

A survey response format designed to measure the degree of agreement or satisfaction (e.g., Strongly Agree to Strongly Disagree).

Dichotomous Question

A question format offering exactly two response choices (e.g., Yes/No, True/False).

Contingency (Skip) Questions

Survey questions presented or bypassed based on a respondent's previous answers.

Double Negatives (Questionnaire Pitfall)

A phrasing flaw that combines multiple negative terms (e.g., "I did not find this visit with my doctor to be unpleasant"), confusing respondents on how to agree or disagree.

Reliability

The consistency of a measurement tool across items or over repeated administrations over time.

Validity

The accuracy of an instrument in measuring the specific concept it is intended to measure.

Pilot Test (Pre-Test)

A preliminary trial run conducted to assess the feasibility, clarity, and reliability of a full-scale research instrument or study.

Data Management

The entire process of record keeping before, during, and after a research study.

Descriptive Statistics

Statistical methods used to summarize and describe sample data without generalizing to a broader population.

Ordinal/Ranked Variable

A categorical variable whose values possess an intrinsic order or rank (e.g., pain scale: none, mild, moderate, severe).

Nominal/Categorical Variable

A variable type consisting of named categories without any natural order (e.g., blood type: A, B, AB, O).

Binomial Variable

A categorical variable that has only two distinct categories (e.g., smoker vs. non-smoker).

Mean

The mathematical average of all values in a dataset; the preferred measure of central tendency for symmetric distributions.

Median

The middle value in a sorted dataset; the preferred measure of central tendency for skewed data.

Mode

The most frequently occurring value in a dataset; the primary measure of central tendency for categorical data.

Range

A measure of dispersion calculated as the difference between the maximum and minimum values in a dataset.

Interquartile Range (IQR)

A measure of statistical dispersion representing the spread of the middle $50\%$ of the data, calculated as $Q_3 - Q_1$.

Normal Distribution Curve

A bell-shaped, symmetric probability distribution where $\text{Mean} = \text{Median} = \text{Mode}$.

Variance

A measure of dispersion that calculates how spread out data values are from the mean by averaging squared deviations.

Standard Deviation

The square root of the variance, expressing the spread of data in the same units as the original measurements.

Confidence Interval (CI)

A computed range of values within which the true population parameter is expected to fall with a specified probability (e.g., a $95\%$ CI).