Non-probability sampling: researchers select people into the study by non-random methods, and noteveryone has the same chance to be included. oConvenience sampling: selecting the most conveniently available people as participants. Weakest form of sampling, risk of bias. oQuota sampling: researchers identify population strata and figure out how many people are needed from each stratum. oConsecutive sampling: recruiting all people from an accessible population over a specific time interval or for a specified sample size.
oPurposive sampling: using researchers’ knowledge about the population to handpick sample members.Probability sampling: random selection of elements from a population. Each element has an equal, independent chance of being selected. oSimple random sampling: most basic probability sampling. Researchers establish a sampling frame. oStratified random sampling: population is divided into 2 or more strata from which elements are randomly selected. oSystematic sampling: involves the selection of every xTHcase from a list. Ex: every 10THperson on the list is selected. Sample size: number of participants. Larger is usually better. Power analysis: researchers estimate how large their samples should be for testing hypotheses. Critiquing sampling plans: oType of sampling approach used (convenience, consecutive, random)oPopulation and eligibility criteria from sample selectionoSample size, with a rationaleoDescription of the sample’s main characteristics (age, gender, clinical status, etc)Data collection in quantitative researchSelf-report data/ Patient-reported outcome (PRO): participants responses to researchers’ questions (ex: interview). Most common data collection approach in nursing. oInterview schedule: when questions are asked orally face-to-face or by telephone. oOpen/closed ended questions. oInterviews vs questionnaires: Questionnaires = less costly, advantageous geographically, economical, autonomity. Interviews = response rates are higher when face-to-face, less likely to reuse to talk, feasible.oScale: device that assigns a numeric score to people along a continuumObservational methods: used to gather information as patients’ conditions, verbal communication, non-verbal communication, activities, and environmental conditions. oCategory system: records events of interest that happen within a setting systematically.Biophysiologic measures: Reliability: extent to which are free from measurement error.Test-retest reliability: replication takes the form of administering a measure to the same people on 2 occasions. Validity: the degree that an instrument is actually measuring the construct it supposes to measure.oFace validity: whether the instrument looks like it is measuring the target constructoContent validity: the extent that an instrument’s content adequately captures the constructoCriterion validity: extent to which the scores on a measure are a replication of a gold standard.