The only way to know if it's not a scam, is to see if they have a working product, or at least a prototype of it. See the quality of the code, or ask an analyst to do this.
Most ICOs have only a white paper. This may not mean it is a scam, but a potential bad investment.
right, look at what has been done by the project developer team that you are interested in because it will be seen if a project is the right goal then they must have made a good result program is still beta or already running.