We estimate the bispectrum of the Very Small Array data from the compact and extended configuration observations released in December 2002 , and compare our results to those obtained from Gaussian simulations .
There is a slight excess of large bispectrum values for two individual fields , but this does not appear when the fields are combined .
Given our expected level of residual point sources , we do not expect these to be the source of the discrepancy .
Using the compact configuration data , we put an upper limit of 5400 on the value of f _ { \mathrm { NL } } , the non-linear coupling parameter , at 95 per cent confidence .
We test our bispectrum estimator using non-Gaussian simulations with a known bispectrum , and recover the input values .