Variables

Model 1

Model 2

Model 3

Model 4

VIF

Beta, t

Beta, t

Beta, t

Beta, t

VIF

Age

0.108, 1.807

0.094, 1.592

0.039, 0.869

0.041, 0.946

1.108

Gender

0.211***, 3.522

0.222***, 3.744

0.096*, 2.124

0.056, 1.258

1.184

Field of study

−0.101, −1.752

−0.098, −1.729

−0.030, −0.700

−0.030, −0.718

1.021

Subjective norms

0.173**, 3.020

0.047, 1.088

0.023, 0.559

1.063

Personal attitude

0.660***, 14.777

0.556***, 11.528

1.403

Perceived behavioural control

0.231***, 4.778

1.413

R

0.291

0.338

0.710

0.737

R square

0.085

0.114

0.505

0.543

R square change

0.085

0.030

0.39

0.038

Adjusted R square

0.075

0.102

0.496

0.533

F-statistic

8.611***

8.976***

56.469***

54.570***

***sig. < 0.001(0.1 percent)

**sig. < 0.01(1 percent) *sig. < 0.05(5 percent)

VIF = Variance inflation Factor