"The object of the proceedings is to achieve a fair trial in the determination of the rights of all of the people involved. Children are harmed if they are taken away from their families for no good reason. Children are harmed if they are left in abusive families. This means that the court must admit all the evidence which bears upon the relevant questions; whether the threshold criteria justifying state intervention have been proved; if they have what action if any will be in the best interests of the child? The court cannot ignore relevant evidence just because other evidence might have been better. It will have to do the best it can on what it has."