Research Instruments, Validity & Reliability

Vocabulary flashcards covering fundamental terms related to research instruments, their characteristics, and concepts of validity and reliability.

A tool used by researchers to collect data for a specific research problem (e.g., tests, questionnaires, interviews, observation checklists).

Research Instrument

An instrument that measures a participant’s ability to perform tasks or demonstrate skills.

Performance Test

A written set of questions used to gather information from respondents in a systematic way.

Questionnaire

A face-to-face, phone, or virtual conversation designed to obtain detailed information from participants.

Interview

A structured list of behaviors or events that a researcher records while observing participants.

Observation Checklist

Able to elicit the needed data without unnecessary items or wording.

Concise (Instrument Characteristic)

Items are arranged in a logical, orderly manner that flows well for respondents.

Sequential (Instrument Characteristic)

Has undergone testing to ensure it measures what it intends (valid) and does so consistently (reliable).

Valid & Reliable (Instrument Characteristic)

Data collected can be quickly organized, interpreted, and analyzed.

Easily Tabulated (Instrument Characteristic)

The degree to which an instrument accurately measures the intended dependent variable without introducing bias.

Validity

Extent to which a study accurately demonstrates a causal relationship within the studied sample.

Internal Validity

Extent to which study findings can be generalized or applied to a broader population.

External Validity

The consistency or stability of the measurements produced by an instrument.

Reliability

Consistency of scores when the same test is administered to the same group at two different times.

Test-Retest Reliability

Degree of agreement among different people evaluating or scoring the same information.

Interrater Reliability

Consistency between different but equivalent versions of a test.

Parallel Forms Reliability

How well the individual items on a test measure the same construct; often assessed with Cronbach’s alpha.

Internal Consistency

A statistic that estimates internal consistency reliability; values above ~0.70 indicate good consistency.

Cronbach’s Alpha

Process of adjusting an instrument so that its readings match a known standard (e.g., a thermometer reading exactly 37 °C for a healthy person).

Calibration

Systematic error that causes an instrument to consistently over- or under-estimate the true value.

Bias (in Measurement)

Using an existing, previously validated tool without modification in a new study.

Adopting an Instrument

Adjusting an existing tool (e.g., changing wording or scale) to suit a new research context.

Modifying an Instrument

Creating a bespoke tool from scratch to address a unique research question.

Developing a New Instrument

A quantitative laboratory method for profiling gut microbiota by analyzing bacterial ribosomal RNA genes.

16S rRNA Sequencing

A rating scale (often 1–5) that measures respondents’ attitudes, perceptions, or frequency of behaviors.

Likert Scale