The manifestation of error in the Image Plane depends upon the nature of the problem in the Fourier Plane and the data time stream

Understanding the Fourier Transform and the relation between the image and visibility planes is critical to successful diagnosis

Errors may be additive, multiplicative, radially dependent, or noise-like

Obvious errors in the visibility data may only weakly corrupt the image; likewise, subtle problems in the data may be readily apparent in the image

Sidelobe patterns around artifacts are not indicators if the veracity of the feature, but are indicators of the nature of the problem

Be careful to discriminate between true errors and filtering or numerical effects due to the imaging, calibration or deconvolution algorithms being used; always know the expected SNR of the data and limitations of the instrument

Image displays and visualization software are powerful tools in combatting imaging errors