At least the effectiveness of it.
Malizz is correct. There are very few true reporters, these day. What we have are "journalists" ... think of writing in your journal/diary, but for public consumption. It's mostly "infotainment".
Of course, there has always been slanted news. When the town paper is owned by an individual, that individual puts their slant on the news they report. When the media is owned by a corporation, who has to get advertisers to pay for the media ... the news is slanted not to offend the advertisers.
Your best option is to listen to news from a variety of sources. And by that I mean, from other nations. Most of the news in America is run through one or two "wire services" - so it's all the same, no matter which media outlet you view. But by listening to the same story reported from other nations, you at least get enough different biases to "read between the lines" and figure out what is REALLY going on.