Before investing in some altcoins i should do some research. I will: read the whitepaper, see if the developers are good(how experienced they are and searching them on linkedin), see if they site is good, whatch the graphs and see if the coin is growing, see if the coin have some good sponsor, understand why this coin is different from others. What else should i search before buying an altcoin?
You also need to join in their community. reddit, slack, telegram, twitter etc. then check if there are new updates or the team always update the community. continuous update is a good indicator of an active development. The indicated road map must be accomplished based on its deadline. changing of roadmap deadline or ICO policy is a bad indicator. this means that the group cannot plan accordingly. If you can't, plan you plan to fail. goodluck for finding good altcoins.