I've just finished reading three articles which aim to measure media bias in New Zealand: David Farrar's 2019 poll survey in Kiwiblog, an ultra-statistical Mediabias.co.nz which analysed thousands of media articles over a year, and Brian Easton in The Pundit, who converted Mediabias's scores into z-scores, with somewhat different results. All made an attempt to scientifically measure media bias.
I tabulated, ranked and compared their results and considered their respective methodologies and personal biases where I could, and I'm really no wiser.