You will have to do several things before joining in an ICO if you want to make sure that the ICO you are joining will really be true to what they are offering in their promotions. First you need to check the contents of their whitepaper especially their vision and objectives and then check their proposed way of addressing the real-life issue their project wants to address. And then look at their partners and potential partners as well as their roadmap. And then of course check the team's background.