QUANTITATIVE METHODS

Research Validity Instruments

Essential Guide

Validity Evidence in Quantitative Research

In quantitative research—especially when using survey instruments—you must demonstrate that your questionnaire measures what it is intended to measure. We do this by presenting structured validity evidence.

Convergent Validity

Shows that items within a construct are highly correlated.

Construct CR (Composite Reliability) AVE (Avg Variance Extracted) Interpretation
Academic Support 0.86 0.62 Established
Learning Climate 0.89 0.66 Established
Motivation 0.85 0.49 Borderline (AVE < 0.50)
Engagement 0.92 0.71 Strong

Rule of Thumb

CR ≥ 0.70 and AVE ≥ 0.50 for acceptable convergent validity.

(Hair et al., 2010; Kline, 2015)

Fornell–Larcker Criterion

Proves constructs are distinct from one another.

Acad. Support Learn. Climate Motivation
Acad. Support 0.79 0.62 0.58
Learn. Climate 0.62 0.81 0.49
Motivation 0.58 0.49 0.76

Diagonal values (bold) are square roots of AVEs. These should be greater than all off-diagonal correlations in their rows/columns.

HTMT Criterion

Heterotrait–Monotrait ratio (Newer standard).

AS LC MOT
AS - 0.72 0.67
LC 0.72 - 0.58
MOT 0.67 0.58 -

Thresholds

  • < 0.85 (Strict criterion)
  • < 0.90 (Liberal criterion)

(Henseler, Ringle & Sarstedt, 2015)

Cross-loading Table (EFA)

Item Factor 1: Support Factor 2: Motivation Factor 3: Engagement
S1 0.78 0.42 0.35
S2 0.81 0.38 0.22
M1 0.29 0.76 0.30
E1 0.32 0.25 0.84

✅ Good items load ≥ 0.50 on their primary factor and lower on others.

📌 How to Report in Your Thesis

In your Results chapter, place the tables and comment briefly:

“As shown in Table 1, all constructs met the threshold for convergent validity with CR > 0.70 and AVE > 0.50, except for Motivation which showed marginally acceptable AVE. Table 2 confirms discriminant validity as all diagonal values exceed corresponding correlations, in line with the Fornell–Larcker criterion.”

Use Case Summary

  • CR + AVE Convergent Validity (Always)
  • Fornell–Larcker Discriminant Validity (CFA)
  • HTMT Modern Discriminant (Optional)
  • Cross-loading Factor Loading (EFA)