Downsample:

Downsample[array, n ] returns a downsampled version of the array by sampling every n'th element.

Downsample[data, 3] 

{4, 8, 3, 2}

Downsample:

Downsample[array, n ] returns a downsampled version of the array by sampling every n'th element.

Downsample[data, 3] 

{4, 8, 3, 2}

Partition with offset

Flatten @ Partition[data, 1, 3] 

{4, 8, 3, 2}