Methods - 1

Operational Definition is

a concrete, testable explanation of how a variable will be measure in a study

Ex of Operational Definition of Stress

it can be defined as cortisol levels, self-reported anxiety, or numers of life events

Reliability is

The consistency of a measure, producing the same result multiple times under the same conditions

Ex of Reliability

a scale that shows the same weight 3 times in a row is reliable

Types of Reliability: Test-retest reliability

checks whether a test gives consistent results over time

Ex of Test-retest reliability

patients score similarly on a stress questionnaire given one week apart (assuming no real change in stress, using the same exact test)

Types of Reliability: Inter-rater reliability

measures how consistent different people are when observing or scoring the same behavior/person

Ex of Inter-rater reliability

2 dental hygienists rate a patient’s discomfort the same way, showing good inter-rater reliability

Types of Reliability: Parallel forms reliability

tests whether two different versions of the same test yield similar results (form A or B)

Ex of Parallel forms reliability

A dietitian gives clients different versions of a quiz (form A or B), and similar scores show good parallel forms of reliability

Types of Reliability: Internal Consistency

A measure of the reliability of how well individual items on a test/scale correlate with each other, measure the same underlying construct, and yield similar results

Ex of Internal Consistency

A 10-item anxiety questionnaire has good internal consistency if all items measure anxiety-related symptoms and correlate strongly with each other

Validity is

The accuracy of a measure: does it measure what it claims to measure?

Ex of Validity

A statistics test has good validity if it accurately measures statistical knowledge rather than reading ability

Types of Validity: Face Validity

whether a tool appears, on the surface, to measure what it's supposed to measure

Ex of Face Validity

a mental health screening tool asking about mood, energy, and thoughts of self-harm looks valid to most people

Face Validity is the

Weakest form of Validity

Types of Validity: Construct Validity

Checks if the test accurately measures the thing being measured (construct)

Ex of Construct Validity

A health anxiety questionnaire has strong construct validity if it measures health-related worrieness and behavior (worry about illness, fear of diagnoses, and frequent health checks) without measuring unrelated concepts like depression

Types of Validity: Content Validity

Checks if the test covers all relevant components of the thing being measured (construct)

Ex of Content Validity

An asthma self-management survey has good content validity if it covers all key areas of asthma, such as triggers, symptoms, medication use, and emergency planning

Types of Validity: Criterion Validity

How well a test’s results match an established measure or real-world outcome

Ex of Criterion Validity

A new fitness test has high criterion validity if its scores are similar to a push-up/sit-up performance (already established that)

• Person A scores high on the new test → they also do many push-up/sit-up

• Person B scores low → they do fewer push-up/sit-ups

Types of Validity: Social Validity

whether end users (participants, patients, students, community members) find a measure or intervention useful, respectful, and relevant

Social Validity is often

neglected, but essential for ethical research and sustained participant engagement

Ex of Social Validity

a diabetes prevention program in Oman that respects local food practices shows high social validity

A measure can be

reliable but not valid

Ex of reliable but not valid

if a scale consistently reports your weight 10 pounds too high, it’s reliable bc it’s reporting this weight multiple times, but not valid because this isn’t your real weight