Conceptualizing Discussions on the Dark Web: An Empirical Topic Modeling Approach

Table 6

Coherence scores for PTM.

k = 5

k = 10

k = 15

k = 20

k = 25

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

CUMASS

−2.7594

−3.2228

−4.3617

−3.2286

−3.2422

−4.1464

−4.9332

−5.6000

−5.3349

−5.7245

−6.0918

−6.2818

−5.6192

−5.8929

−5.1314

STDEV

0.8246

0.5260

0.3357

0.2833

0.3857

CUCI

−1.6422

−1.6884

−2.8125

−1.1733

−1.2654

−1.6247

−2.4025

−2.9046

−2.3484

−2.5830

−3.1505

−3.1279

−2.5562

−2.6753

−2.0936

STDEV

0.6628

0.2385

0.3067

0.3213

0.3073

CNPMI

0.0040

0.0159

−0.0400

0.0500

0.0510

0.0363

0.0006

−0.0212

0.0038

0.0045

−0.0281

−0.0283

−0.0013

−0.0040

0.0272

STDEV

0.0295

0.0082

0.0136

0.0189

0.0173

CV

0.6261

0.5835

0.5630

0.6679

0.6846

0.6669

0.7305

0.7329

0.7404

0.7662

0.7396

0.7682

0.7556

0.7724

0.7662

STDEV

0.0322

0.0099

0.0051

0.0160

0.0085

k = 30

k = 35

k = 40

k = 45

k = 50

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

Run 1

Run 2

Run 3

CUMASS

−6.1779

−6.5790

−6.5684

−7.0443

−7.1310

−6.0683

−6.6276

−7.4835

−6.5795

−7.0071

−7.2680

−8.1403

−7.6360

−7.6998

−7.9449

STDEV

0.2286

0.5901

0.5086

0.5935

0.1630

CUCI

−2.7979

−2.9666

−3.0278

−3.2830

−3.4885

−3.0848

−3.2884

−3.4900

−2.8800

−3.3357

−3.4175

−3.8774

−3.4186

−3.7675

−3.8211

STDEV

0.1190

0.2019

0.3108

0.2920

0.2185

CNPMI

−0.0098

−0.0136

−0.0267

−0.0356

−0.0386

−0.0182

−0.0316

−0.0413

−0.0172

−0.0346

−0.0312

−0.0527

−0.0309

−0.0462

−0.0486

STDEV

0.0089

0.0110

0.0121

0.0116

0.0096

CV

0.7700

0.7713

0.7729

0.7582

0.7964

0.7906

0.7929

0.7781

0.7756

0.7987

0.8126

0.8042

0.8074

0.8173

0.7880

STDEV

0.0015

0.0206

0.0094

0.0070

0.0149