Statistical significance considers the first and third of these concerns. The middle one, bias, cannot be detected by mathematical deductive logic: it needs detailed information on the way the sample was chosen. This is dealt with in the notes on bias.
A HEIC file is a raster image saved in the High Efficiency Image Format (HEIF), a lossy compressed format. It may contain still images, image collections, image bursts, or image sequences, along with metadata that describes each image. HEIC files may also appear as .HEIF files.
Convert iOS 11 photos from HEIC to JPG Apple has just released iOS 11, and one major change is the way recent iOS devices (iPhone 6s and later) store photos. Apple has adopted HEIF (High Efficiency Image Format), which creates photos that take up less space than JPEGs.