This is Very True on Wall Street!
There are many articles written about stocks on Wall Street. Common advise like buy stocks with low P/E (Price/Earnings) ratios, buy growing companies or buy companies liked by analysts fails to produce above average returns for the typical investor. Utimately, some of these methods work in certain markets, or at some periods or time, but there is very little publicized research that shows something that really "works." This may well account for investor returns and investment management returns, which typically underperform the market as a whole. (The brokers get to enjoy nice boats with high trading fees.) Very few people do their own "true" (scientifically valid) research. There is a little truth to each of these varibles. I recall one article which had conglomerated about 200 variables, each of which had a 0 to about 2% correlation to stock returns. Most of these variables had 0.5% to 1% correlation. Such a correlation shows some value, but ultimately is worthless as far as being an effective investment tool. Most "research" sent out by investment houses is purposed with "selling" stocks to investors. Brokers make money when you invest so calling you up and telling you their research analysts found a value is solely to get you to buy so your generate a commission.